Hi. First of all drain the gearbox oil or if you are a tight Yorkshireman like myself lay the bike on its right hand side to stop the oil draining out.
Next remove the gear lever then the circular clutch cover. This will expose the clutch unit. Undo the six ( I think ) bolts with springs and washers, with these removed you can remove the pressure plate this will then expose the plates which you can remove by sticking your fingers in the grooves. If you do this with bike upright the only thing to watch out for is the ball bearing falling out from within the mainshaft.