Yeah, I used an impact hammer on them (gently) after trying all the things we usually do... I figured BEFORE I broke the bolt off somewhere downn the shank and also leaving a sharp edge I'd use the center of the phillips head to use for starting my drill bit. Worked great. I was worried about grinding/cutting the bolt heads off and not cutting into the sheet metal of the fender in the process. Thought it was worth the effort to do it the long way.
Something to note here was the hardness of the stock bolts used. WOW. I could only drill with an 1/8" cobalt bit for the starter hole- not one type of bit would drill through a bolt that didn't have a starter pilot hole already.
Unless I was moving up in 1/32" increments my high speed drill bits wouldn't cut at all. I was sharpening my drill bit after every every hole. In other words I must have used my drill doctor about 30-40 times resharpening. I tried a couple brand new high speed steel bits (spares I keep) and they didn't work any better.
Anyway, it took a couple hours but the holes are "smack dab" in the middle but I will now use Riv-Nuts to hold the fenders on... and lots of anti-sieze!
