Yup. If I used a tool at all, it would be a bit of wood (sometimes that sheet metal can be hard on the fingers.) NOT as a stiking implement, but to press with (gently) In general, unless this is something you do a LOT, if you grab the mag with a pair of pliers, or stick it in a vice, etc, you are gonna overdo it. And then you are posting in the want ad section, looking for a replacement mag. Seriously, gently does it. When the lips get a bit deformed, it is usually very slight, and you just want it back the way it was.