>>7229878>>7229879Get a mechanical pencil that you can change the eraser on and use that as the gripping tool. I recommend these for the erasers themselves. This pack can be purchased at any Office Depot-type stationary/office store. You want the type of eraser that crumbles, not the vinyl erasers that have concentric rings visible on the tops.
Get some scotch tape and touch the sticky part with your hands to get rid of most of the adhesive. A lot of times the printing on a head is so weak that putting a piece of tape over it and pulling it off takes some of the printing with it, so you want the tape to be just sticky enough to hold still if you accidentally bump it with the eraser.
Before you start putting down tape, plan out the sequence that you're going to apply it. If you're just removing one small detail you probably only need to put down one piece of tape and remove it immediately after taking care of that detail. In another situation, you might have to apply, remove, and re-apply tape all around an area (like I had to do removing the mask without touching the eyes or mouth). By planning out exactly how you're going to remove it step by step, you can avoid pulling the tape off of the printing more than you absolutely need to.
Then you basically just rub the eraser against the exposed printing to erase it. Sometimes it comes off right away, sometimes it takes a few minutes. If it's really tough you might have to use Brasso (metal polish) and a cotton swab, but for most jobs an eraser works just fine.