The important thing to remember when removing the piston and sleeve ........make sure you put it back in EXACTLY the way it came out. If you reverse the sleeve, it generally wont run, or run very badly. If the sleeve has a recess for the crank counterbalance, it's gonna hit and do damage.

Same with the piston. Some piston/rod assemblies use a little spring or sur-clip to hold the piston pin in place. If the piston is put in backwards, it can catch a port and ruin your day for a long time. Some piston skirts have reliefs on the bottom edge for crankshaft clearance, or port timings.

BEFORE you remove the piston OR the sleeve, mark it with a marker (do not scratch a mark) and remember the way it came out.