hi paul, your lock may be working ok but the latch may not,if you put a mica card between the door or doors slide down to latch and it will probably slip it.If not put your foot on bottom of door apply a little pressure and there is a catch on the other side,get small screwdriver slip catch away from you,that should release catch, do the same with top, when doors are loose push both and they should come apart.If not get a 14lb sledge good luck.
mick the pick, January 2007