Engine won't crank

I have a Mitsubishi Diamante (1998) it will not crank. I have tried charging the battery. There is a spark at the starter motor because I tried jumping it with a screwdriver. I have good power to the radio, and lights. When I do try to crank it and let off the switch I get a clicking sound where the relay fuse or switch is. I'm at a loss with this. If it is the starter, how do I get the dang thing out !! I only see one bolt and I'm sure there is more. Please reply. Thanks