It doesn't have to be complicated. The distributor turns clockwise, so loosen the clamp at the bottom and turn it counterclockwise a little at a time. If you have a dial-back timing light, use that to advance the timing another 3 to 6 degrees BTDC. When I lived just west of Denver (6,000'...
You'll get the most bang for your buck by far, by just advancing the ignition timing once you get to Colorado. It makes a lot more difference in drive-ability than changing jets, and is easier to do.