Taking clutches and gearboxes apart is a serious venture for a biker. Have you looked on U Tube to see if someone has video'd it. I guess the Hays manual or Work shop manual says it is an 'expert' level job, with proper workshop facilities. Before you split the cases and the like try to identify the problem, if you can. Also, if you do take everything to pieces it is worth thinking about what else could be changed or upgraded ... before you re-assemble. Good luck. Richard

Finally ... if you are unable to do the work yourself, then the bike is likely to be an economic write-off .... but I guess you've worked that out. Sell the bike for parts and get a new bike ...