If you decide to work on the engine, you should know, what you´re doing, and you should know about basics like how to properly adjust valves timing. If you´re not sure, better ask a qualified mechanic. Also, I do my very best to tell the correct things, but of course I can't give any warranty!
Best, put the bike on the sidestand, and do the following steps:
Once you have removed the cover, you'll see the clutch. Block the engine with the blocking tool, or, if lacking, a clean piece of cloth, as seen on the pic. Losen the four 10 mm screws of the clutch plate and remove the plate. Carefully open the securing of the 24 mm central screw. Now, once the plate is removed, you can't block the engine as easily as done before. If still lacking a blocking tool ;-), you may either put the engine to first gear and draw the hand brake (block it with a strong rubber band or something like that), or, maybe better, screw in the four plate holding screws, with springs (use some suitable washers), but without the plate. Now losen the 24 mm screw. This will take some amount of power ... In any case, don't try to block the engine like this!
Now remove the complete clutch. Reinstall all metal rings, put away old friction rings, and install new ones, piece by piece. Reinstall the complete clutch, tighten the central screw with a torque of 80-100 Nm, secure it. Reinstall (new) springs, clutch plate and tighten the four 10 mm screws with a torque of 8-12 Nm.
Remove the remnants of the old cover gasket from engine housing and cover. Don't use a screwdriver or a knife for doing that, it may destroy the surface. Use a special scraper, you may find it in your local tools' shop or at your local aftermarket parts provider's. Be sure to remove all remnants, and don't leave them inside the clutch housing ... Reinstall the cover (don't forget the gasket), the pipe (don't forget the gaskests) and all the other stuff, and adjust clutch play to appr. 2 cm at the end of clutch lever. After filling in new engine oil (2.2 l without, or 2.4 l with oilfilter changed), you can go out for a ride and test it.