How can i fix my hotpoint FFA74 fridgefreezer?

The freezer door will not shut properly, i took the freezer doors out and the door shut properly. Looking at the back of the freezer, it appears that the back has bowed slightly and therefore is pushing the drawers out and restricting door closure. Could there be a build up of ice behind this panel? There are 4 screws holding this panel to the back of the freezer, is it safe to take these screws off? or should i defrost the (frostfree) fridgefreezer and see if that works?
Many thanks

Alex Pitter