I haven't done this, so I'm sure someone w/ more knowledge can provide a better answer... There's a rubber nipple that you can cut and feed wires from under the dash, through the firewall.
Or, you can do what I did and use an add-a-circuit, so you have a fuse and you run it from your fuse panel under your dash.

I want to change the 12v outlet in the shift console to constant 12v but don't know how to get the console apart to get to it. Can anyone help?

well what i did was take the console out by pulling up on it but be gental and remove the wires to the 4 way signals then take the 2 screws out and gentaly pull the console out but be careful the connectors for the 12 v outlet are still connected pull them off the run a jumper wire directly from the battery into the cab then cut the positive wire then use a butt connector to connect the wires together and then reassemble......DONE

why is this thread even in the DIY section?