Originally Posted by skids
Help me understand how driving up on blocks will help to change a tire.
Like they said. Because of the way your tires are mounted together, if you raise one, the other will follow pretty quickly. Therefore if you use the lego blocks or blocks of wood and create a pretty steep and tall block (usually 6 or 8" or so) and pull the good tire up on that block, it will suspend your bad tire in the air.
That is the preferred method, because it doesn't concentrate all of the trailer weight on the frame or axle tube. Just remember to loosen the lugs BEFORE you get the wheel in the air... or else you will piss off the wife by having her hold the brake activated while you try to loosen the lugs.
Hopefully nobody ever has to learn this lesson. Thankfully I never had to on the side of the highway!