Cut the wire leading to the tranny, splice in a couple of longer lengths, and put a switch in the dash. Now you have selectable AWD to 4wd.
that's what i did.
The computer most probably won't freak out either
mine does no "freaking out", works fine. the only thing that happens out of the ordinary is this....if you leave it "on", in other word the wires disconnected when you start the car (where normally that wire is single strung to the solenoid), the POWER light will flash on the dash. the POWER light flashing indicates the TCU sees a problem. the problem is only in the placement of the switch though - one position completes the circuit and there is no problem, the other position disconnects the circuit which isn't the normal condition of the circuitry so the TCU sees that and flashes the POWER light on the dash. basically the TCU wasn't designed with a switch in mind, so if you have the switch breaking the circuit when you turn the car on it will "think" there's a problem when there is not.
that's about right, easy job. basically most of the time is determining where/how you want to mount the switch, the wiring is easy. cut one wire and install a switch and you're done.
it's a 20minute job to put a switch in.
i used a 2 pole switch with a light so i can tell when it's "locked".