Take the caliper ones off first, it will give you more room to get to the bolts. You could slide a 2ft pipe over top of your wrench to give you more leverage. Most importantly, you need to have be sure that the socket is fully engaged on the nut. If your socket is bottoming out, get a long socket. Also, make sure you are using a 6 point socket and not and 12 or 18. A 6 point socket is the only way to get the grab you need, 12's and 18' are thinner sidewalls and can flex.

-Andy

Andy W. The problem with America is stupidity. I'm not saying there should be a capital punishment for stupidity, but why don't we just take the safety labels off of everything and let the problem solve itself?