[magman]

To re-tap, you need a tap and dye set. It is easy to do w/the right tools. You need to take your time and go slow as you re-thread.

I would not try to re-thread just by forcing a screw in.

Basically, w/a tap/dye set match up the threads of the screw you intend to use w/the correct tap. SLOWLY screw tap into the existing hole...screw about 1/2 turn than back the tap out. You will feel resistance as you screw the tap in...it is normal. Continue to work the tap in and out. When you are done, the tap should screw in as would a normal screw.