Hello! I've just obtained Wilson combat +2 mag extension for my 870, and need advise on install! I am aware that there are 2 dimples that need to be removed to allow clearance for additional shells in the mag. tube. I was just curious on how you guys went about this! I do know Brownells sells a tool for $80 that has mixed reviews, but I really don't want to spend that kind of money.... I have heard of drilling or filing ? Any input would be appreciated! This shotguns primary use is home defense, but may be restored to original setup for field use. Thanks!