I recently acquired a new Martin Threshold (70# model) for Christmas, and it came with a 30" draw. I want to adjust this to a 28" draw, and I have the appropriate modules to do so. However, when I went to unscrew the screw on the back of the cam to release only the module, the back screw was blocked by the limb. Any ideas as to how to get access to this screw so I can replace the module. The other screw came out just fine.