I swapped a TRD axle for my non-TRD axle to have a selective locker in my truck. I purchased the Downey Cable Locker conversion kit. The install was a bit slow, and required some finesse, but the results are well worth the efforts. These pictures and steps are a bit rough, but the directions are complete enough that I didn't feel it necessary to go into extreme detail. One thing I recommend when doing this kit: DO NOT USE THE INCLUDED FREEZE PLUG! Simply remove the plastic gear from the actuator, and re-bolt the actuator to the axle. You have to do a little grinding to the actuator to make it fit again, but the freeze plugs don't fit right, and the one in my kit fell into the diff. Chad and I spent an extra 2-3 hours pulling and replacing the 3rd member just to get the freeze plug out.

Here's my TRD axle from a wrecked '99 Prerunner.

The truck on jack stands.

Sorting the parts.

The shifter cable.

The hole that the cable will run through and enter the cab.

Removing actuator.

Attaching Downey shifting fork attachment.

Chad (aka notrub) helping me adjust the linkage.

Completed kit.

Shifting handle under driver's seat.

In perfect reach to lock the locker, yet out of the way completely.