Is there an easy way to remove dents from an SM58 mic grille?
Purchase a wooden handle for a file. Make certain the handle has a rounded end.
Remove the SM58 grill and place it over the round end of the file handle. Place the other end of the file handle on a horizontal flat surface. Use a small hammer and gently tap the dents using the rounded file handle as support on the inside of the SM58 grill.
With time and patience, most dents can be removed or improved.