Basic Ingredients are:
A switch (one with nice fat quick-connect tabs on the back is dandy, the one I use is a snap-in type from Home Depot)
Wire (Nothing too big or small, remember it's much easier to solder when the internal wires that make up the wire are very fine, rather than thick).
A utility knife, or dremel if you have surgeon's hands.
Soldering equipment
At least 2 quick disconnect female tabs for the back of your switch, more if you're not going to solder.

Take out the center console. (start at the rear, 4 screws on side and 2 under plate under parking brake, then two on sides of console in footwells, take off shift knob). Once you've gotten this off, get under there and remove the two pain in the ass 8mm bolts that hold the radio and pocket assembly in place. Slide out the radio, and disconnect the rear wiring harness and antenna wire. (The antenna wire is for reception, not for your POWER ANTENNA. Just so we're clear).

Remove the plastic pocket from the radio, and measure your switch. Cut a hole in the back of the plastic pocket wherever you want the switch, here's a rectangular switch with a hole cut on the side of the pocket (will be drivers side). Don't forget to check what positions are ON and OFF, so you have them the way you want them.

Now, find the power antenna wire, which is yellow with a green stripe. Cut it, leaving enough room to solder or put a quick-connect, and strip the wires accordingly.

Take your extension wire, 6 inches to a foot is more than enough, depends on how much slack you want. Don't make it too short, or it'll be a pain to put in when the radio gets in it's hard to access hole. Much easier to plug in while you've got full access and then put the radio in. Solder the wires together.

Once you've extended your two wires and put the two quick connects on the ends of the extentions, all that remains is to plug it in!

Our two quick connects fit snugly over the male tabs on the back of the switch, and we've got a function antenna switch. Put it all back together, and you get...

A sweet, discreet antenna switch.