What size allen wrench is needed to remove the factory radio? I saw a thread where someone thought it might be a 3mm, but didn't seem to be sure. I've tried all of my allen wrenches in metric and none of them seem to work.

My radio code won't seem to enter in spite of several attempts using the code that was written in the owners manual, and the directions I've seen from Shogun. I can replace the radio with an aftermarket unit I have, but need to know what tool is required to remove the factory unit.

Thanks.

Eric