I went to Strauss Discout Auto and purchased three cans of R-134a refrigerant (12oz cans, $6.99 each), and one "R12 to 134a Conversion and 134a Recharge kit" ($29.99). Total cost $50.96 plus tax. You actually only need two and a quarter cans, so I used the rest on my mother's 1994 Jeep Grand Cherokee (which was easier to work on, btw...) Fortunately, I have an SLC - all bets are off with the R12 system in the G60s.

First you need to locate your A/C service fittings. They should be in the back, by the firewall on the passenger's side. There should be two metal hoses running forward, and if you're lucky, one has a sight glass. There are your high and low pressure service fittings. The low pressure one is the one closer to the strut tower, the high pressure one is the one with the sight glass right before the fitting.

Remove the dust cap from the low pressure fitting.

I then took the hose that came in the kit and attached it to the fitting. One end slides on, the other connects to a valve that screws into the top of the can of refrigerant. Screw the valve into the hose, and then into the refrigerant, making sure to have the valve set to not puncture the can yet.

Start the car and put the A/C on maximum.

Turn the valve, hold the can upside down, and let the freon drain into the system. When the can is done, remove the fitting from the low pressure fitting, close the valve, and attach the second can. Repeat the process.

When the second can is done, do the same thing, except instead of refrigerant, use R134a A/C system oil. Mine came in the kit, however it's available seperately, for approx $3 a can. Empty the oil into the system making sure that the can is held upside down.

Remove the hose from the low pressure fitting again, and attach the 3rd can of R134a to the hose, repeating the above, except this time hold the can upright. This allows the freon to flow as a gas instead of as a liquid (when held upside down) and balances out the system. Wait a little while, close the valve, remove the hose, replace the dust cap, and enjoy your nice cool air conditioning!

Note - if you have leaks, you're going to find out quickly when your A/C suddenly stops working. If you have a leaky system, take it somewhere and have the leaks fixed, and then recharge.