I've said I was going to do this for a while so here it is:
Cooper STT 37x12.5R17 on MRW 17x9.5 rim
1 Tire Spoon (I use Euro style because it has a little hook on the end and it slides better.)
Use soapy water to lubricate the tire. It makes it easier to slide on the steel.
To install make sure inner tire bead is under the outer lip on the wheel.
You can use your foot to keep the inner part of the tire from poping up when you start to run the tire bead.
Work the bead in 2" lengths alternating sides. Take it slow---it doesn't pay to try and take big steps because you can damage the tire.
As you reach the end, you may not be able to get the tool between the tire and wheel. You can lift up a little to assist but usually if you have 6" or less a good kick it with your heel and it will set it.
Here is a picture of the inner tire wall on the rim. My inspector is looking for debris that may have fallen in.
Now for the fun part. (YES, that IS sarcasm.)
Place the outer tire bead under the outer wheel lip. It won't want to stay there in the beginning. Some tires like BFG have very plyable sidewalls and you can work them on the ground.