[cabmandone]

Get a grinding wheel for a 4" hand grinder and hit those spots. Use it to feather into the clean stuff and call it a day. I bought a Bosch diamond wheel for my hand grinder that worked great! I tried one of the cheap ones and it marked the surface too much. The Bosch seemed to work well.

Oh and Spike Shoes! Don't forget spike shoes!

I used about a 5 gallon bucket of flake on my 24x40 and came out with a really nice heavy broadcast look. I don't recall what size your garage is but it seems like with a 5 gallon bucket you're going to be close to a full broadcast which will be very little of the epoxy paint showing. This is where the spike shoes come in really handy. You can just walk around tossing the flake until you're happy.