Its easy as cake, 30$ for a big can at any auto store these days.
Yes, the valve near the firewall, you may need to move a few wires over to connect the valve.
Don't go over 45 PSI, or your AC will not work as well and your system can be damaged. IE: Replacement parts = $$$
To CORRECTLY do it, you need to do a leak test to see if your system has a leak, if not: evacuate the lines with a vacume pump, fill to a specific, low, PSI with oil, run the AC for like an hour, and then fill with refridgerant.
If you have a leak, you oughta take it to a shop unless you really know what your doing - and shouldn't be reading this advice anyways.
I didn't do that, I just filled mine back up with one of those kits. Not quite as cold as a properly done job but it works none-the less.
Last edited by bitcore; 05-21-2006 at 08:29 PM.