Clutch & start button not working?

Can anyone help me to try to fix this issue, 2005 megane expression (less than 60K on clock) start button & clutch not working & wont start my car (but brake & clutch does start my car) Any ideas how to fix this without taking to renault dealer & get ripped off Also got issue with electric window stopped working, tried fuses but still no joy - thinks its either the regualtor or the motor - can anyone give me a step by step idiots guide on how to get the inside door panel off so I can replace the parts??

THANKS, much appreciated