fuel filer panel

hi, can anyone point me in the right direction just recently the fuel filer panel has got a bit temperamental when you give it the little push to click it open it isn't opening, so i thought i had better look into it before it stops altogether and i cant get any fuel in. 1st question is there a way of opening the flap manually ? 2nd any advice on what the problem could be? 3rd is there some kind of tutorial on how to take it apart without braking it? many thanks kev!