Clean the bike and engine.
Have a clean work area.
Remove the tank, seat, sub-frame, carb/intake/reeds, and exhaust.
Drain your coolant from the radiators and water pump.
Disassemble the top-end with the appropriate wrenches. Pay particular attention to the powervalve assembly taking pics for reassembly. IMPORTANT: Be sure to coverup the bottom end to prevent anything from falling into the cases!!! Shop rags work well for this.
Clean everything thouroughly!
Besides gaskets, you will need to inspect the bore/plating and overall dimensions. This requires some specialized micrometers and is best done by a reputable mechanic.
Once you have the dimensions and plating inspection, you can order parts. Being an 2001, your cylinder may need to be bored and replated. If you do not have a manual, order it now.
Reassemble per the manual and break in. Work time will likely be several hours your first time. Other work will be dictated by the inspection and ordering parts will likely be several weeks.
BTW, if a top-end has not been performed on the bike before, a bore a replating is almost assured. Failure of a piston skirt can cause catastrophic engine failure and be MUCH more expensive to repair. Don't put this off!