The OP might have solved his problem, but the question and suggested answers may help someone (who hasn't seen this thread) running into that same situation. No harm or foul by bringing it back is there?
2XI would try to glue in a dowel first , and redrill a new hole, but sometimes getting the right dowl to fit might be tricky, especially if you wood is only 1/2 inch thick.
You could try using a block of wood as a guide for the forsnet bit.
What I would do is get a nice hunk of hardwood (perhaps maple) and a 10mm forsner bit. Put the bit in a drill press, and drill a hole in the hardwood at the angle that you want your hole to be in the musical instrument that you are repairing.
After doing so, you can clamp the hardwood guide over the existing hole and drill away. The hardwood guide would help prevent any tear out if it is flush with the musical instrument, and the forsner bit also will help prevent it as well.
Hope this helps... if you need a picture to show you, I might be able to get something put together.... just let me know.