Problems with spoiler...WTF...do I do???

well...it's not that seriouse (I don't think). I took my supra spoiler off a while ago. The bolts that attach it to the trunk were rusty so I had to drill them out. Now there is just stubs coming out of the spoiler. I sold it to someone and I want to know what kind of advice I can give him on how to bolt it back on.

I was thinking that he should drill the rest of the bolts out completely and just bolt it on from the under side of the trunk. I was thinking that bolts with wide flanges should do the trick but I'm not sure....