Increasing centerbore

[Mr. Pockets]

So I have this set of 13" alloys off a Celica, and the centerbore is too small. I need to machine them out some so they fit on the Justy.

I actually dropped them off at a shop, but they want $40 each to make a hole bigger. I'm so uncomfortable with this price that I think I'm going to go take my wheels back before he does anything.

Can anybody htink of a way I could increase the centerbore on these wheels? They'll only be used for autocrossing, and at least never be on the freeway. The new centerbore doesn't even have to go all the way through.