You need a quality set of machinist needle files, a magna-visor, Q-Tips, some flitz, a few tongue depressors and some steel wool.
Leave the power "electric gunsmith tools" for less important items. You can remove too much material.
Use the needle files to remove the minimum amount of material to, use the Q-Tips to verify that you are making progress, finish up with steel wool wrapped tight around the tongue depressor coat with flitz and give the "reworked" area a massage.