(Fig.1) The Seals
While the forx were in bits I wanted to replace both the oil and dust seals (yep thats them on the left). These can be found for about £14 in good bike shops or ordered from a host of places online. One Caution: make sure you know the stantion width of the forx your buying them for.

(Fig.2) The Forx
Well here you have it, your standard, common or garden Z1. Its the MCR version and I think I've used the lock-out feature about 5 times in 2 years.. bonus! For this 'article' were gonna strip the thing RIGHT down to a pile of bits! That way you will know how to get at and replace ANY part of the fork.

(Fig.3) Remove Pre-load nobs
The first things to be removed are the lock-out lever and both pre-load adjuster nobs. The Lockout lever (left leg only) is held on with a very small button-head socket screw screw (A). The two nobs are each fixed with a small set-screw (B) which also needs to be loosened (But NOT removed) with a hex key.

(Fig.4) Remove stop-ring
Under the preload nobs on both sides you'll find a small sprung stop-ring that stops the cartridge being wound into the leg too far. These need to be removed with a small flat screwdriver inserted into one of the two gaps you will see. Just twist the screwdriver gently and the stop-ring will pop out.

(Fig.5) Unscrew the caps
Now you should be able to fit a 7/16th's socket over each cap and unscrew them. Note: It's possible to undo the caps with an adjustable spanner but I seriously recommend that you don't, the Ali is rather soft and easy to damage.
 
(It probably doesn't need to be said but the caps unscrew ANTIclockwise!)

(Fig.6) Remove caps completely
When both caps are completely unscrewed remove them and you'll be left with the threaded tops of the piston shafts. At this point, as the oil bath is no longer air-tight you can push the stantions right down into the fork legs; Be warned: If you do this very fast your likely get oil bubbling over the top, so just gently slide them down.

(Fig.7) Remove Springs
The springs are held in with a reverse-threaded (left-hand / anticlockwise) check-nut (A) and a nylon washer (B). Remove both of these and pull the springs out over the hydraulic cartridge ends. The springs have been immersed in the oil bath so be careful not to drip dirty lube all over your mums sink.

(Fig.8) Drain the oil
Note: If your simply replacing springs and the oil is clean/new you can ignore this step and go directly to REBUILD
 
Old oil is often rancid and stinks so you might want to do this outside. Drain it into a disposable container, ideally something with a sealable lid.

(Fig.9) Remove Foot-Nut
The hydraulic cartridges are bolted in with a foot-nut (A) which is recessed inside the bottom of each leg. This nut must be removed with a 15mm socket because a ring spanner or similar won't reach far enough into the leg. Once the nut is free it's possible that a small quantity of oil may seep out.

(Fig.10) Remove & Drain cartridges
Warning: The carts are likely to be full of oil and if you compress the piston when the blow-hole (A) is NOT aimed at your drainage container, you'll probably shoot dirty oil everywhere like I did (gimp!).
So... when they ARE aimed in the correct direction, pump the carts repeatedly to drain all the oil.

(Fig.11) Remove Top-Out Springs
Held between the cartridge and a stop on the inside of each stantion is a small Top-out spring. These should slide out easily when the fork is tipped upside-down.

(Fig.12) Lift out stantions
Now the innards have been removed you can draw the stantions right out of the fork legs.
Note: These stantions are specially coated to slide very easily against the dust and oil seals so be careful not to damage them in any way (i.e. don't throw them in a gravel pit).

(Fig.13) Prise out dust seals
The dust seals can be gently 'coaxed' out by inserting a small flat-head screwdriver under them and levering. Do this from several different angles to draw them out square. If the seal gets stuck (like one of mine did) use pliers to yank it out! Take care not to 'stab' the or damage the inside surfaces or top of the fork-legs though.

(Fig.14) Remove seal-stops
The oil seals are held in with a sprung clip that sits slightly recessed into the fork leg. To remove these clips insert a small screwdriver between the clip and leg-inner and lever them out as shown.
Note: The clip should offer no resistance but if it does, again be very careful not to stab/damage any of the surfaces.

(Fig.15) 'Pop' out oil seals
This seems to be the area most people have trouble with. The oil seals are pressed tight into the legs and need to be levered out with considerable force. I suggest you use one of the old dust seals to protect the top of the leg while doing this (as shown). The seals will POP out very fast. Both of mine hit the ceiling and left two oily marks!

(Fig.16) Remove washer & bushing
Sat bellow oil seal is a washer and under that a pilot bushing. Remove these parts from both legs.
Warning: The Pilot Bushing is made from very thin aluminium and can be bent easily. This part needs to remain in shape and un-kinked in order for the stantions to slide inside the legs properly and without hindrance.

(Fig.17) Fork-Strip complete..
Ok, so now you should have pile of oily dirty crap requiring some cleaning. Everything that isn't to be replaced with new parts should be wiped down with a Teflon (PTFE) spray like GT85, KT3 or similar. The lower fork legs will probably be lined with a slime residue from the old oil and this can be blasted out with the Teflon spray. If you decide to use some heavier cleaning material like degreaser etc be absolutely sure that it isn't going to attack the nylon/plastic parts and stickers.
If this strip and rebuild is a rush job and you didn't have a chance to get hold of any Teflon spray or degreaser then you *CAN* clean everything the traditional way in the kitchen sink with LOADS of detergent (washing-up-liquid). Be warned though, if you decide to do it this way you must (a) be prepared to have to use vast quantities of your mums fairy liquid and (b) realise that every part must then be rinsed of even the tiniest trace of detergent with clean water. All the parts must also be totally dry before any new oil touches them. I have often found the oven a good place to dry out bike parts quickly :)
Once you have cleaned EVERYTHING you should have a clean shiny pile of crap ready to be reassembled (as show above)