Just a few notes about taking apart an Intel Mac mini.
When you're taking out the corner screws, loosen one at a time and flip the Mini over to shake them out. One of them is longer than the others and it matters where it came from.
After you take the Airport antenna off its post, when you take the carriage out of the base, it may come loose from where it connects to the motherboard. Just let the shape of the cable be your guide to where it should connect to and then snap it back on when you're putting it back together.
And when you put it all back together, be sure to reconnect the little fan control cable, or else the fan will run on high all the time. :-)