Keep a long steel "fixin pipe" around, you can put it on the ends of wrenches and get tons more leverage
uhh this is aq good idea to undo stuff but DO NOT use it to tighten things, it will WRECK THEM, me and my brother both used it on our crank arms to tighten them when they were loose, when i wanted to replace mine, i couldnt get the crank arms off, i ended up having to use a heavy duty grinder to cut them off and it cost me several hundred pounds to replace all of the parts that were damaged.... dont ever try cut the spindle with a hack saw....