Couldn't be easier - XS Sight Systems Magazine Tube Detent Swage - Rem 12 ga RE-7000-1

Reluctant to drill out the detents, and create additional entry points for dust/grit, I spent a few dollars on this tool. And am glad I did! The procedure took less than 10 minutes and required no additional sanding or filing. I used a brass punch for final finish to avoid marring the original bluing on the magazine. Also used a 1" scope ring around the mag tube upon insertion of the swage to avoid any possible distortion to the metal. The result was better than expected and worth the expense of the tool.