what are you wanting to do with it?
You’ll need the castle tool for the cartridge and I would advise not to touch the bearings if you can get away with it. If you can flush them through with degreaser and regrease with a grease gun that would be as far as I would go.
See this for pictures.
here
Generally it goes something like this.
let the air out of the fork.
take the lockout lever off.
use a pin spanner to unscrew the alloy top.
this should lift out a bit as you compress the fork.
You will see the top of the cartridge. insert the castle tool and undo the cartridge.
pull out all the gubbins, the air bit may be stuck in the bottom of the headtube, you’ll need to tap that out gently.
remove the negative spring (this does vary, but in general any retaining bits of plastic will unscrew)
undo the plastic top bit of the cartridge.
remove the innards of the cartridge.
do this while holding the cartridge over a bucket to catch the oil.
clean and inspect everything.
pu the piston shaft back in the cartridge, fill with oil (2.5- 15wt. standard is 5wt), cycle the piston a bit, top up with oil and reinsert top cap. There may be a bleed valve on the side of the cartridge, open it until you have the cap on, then close it off once excess oil has ran out of it.
clean it all up, reinstall everything including the air bit, grease it all and reinsert into the headtube.
pump it up and hope for the best.
