Shift Lock ECU Replacement -How to?

Hello everyone,
I am new to this forum and hoping I can get some help. I have a 2007 Tacoma crew cab 4x4 SR5 and recently I noticed that my RPMs (3000 at 60) were high when on the high way and engine sounded as it was working harder so my first thought is that it is not shifting into 5th. In doing some trouble shooting I also noticed that when switching from D to 4 on the shifter does not show a decrease or increase in RMP like it had in the past. 4x4 is working fine and all else seems to be working just great.

I took my truck to the dealership thinking it was their fault since they just did the frame recall but they found that the Shift Lock ECU (AKA Shift Lock Control) was bad. This part is apparently in the cabin underneath the center console by the shifter and since they did not touch that would not replace it. Well the cost for them to spend 1 hour changing that out and the cost for the part would have been $600!! Well I did what anyone else with a little mechanical ability would have done and said Fudge That I will do it myself.

I bought myself a Repair Manual so I can do this but to my dismay it is not in the book. I did find a diagram online that shows where is at and doesn't "seem" hard to replace. Before I go out and buy this $300 dollar part I want to make sure I know what I am getting into.

Do any of you gurus have experience replacing this part? If so is there any kind of calibration needed? know of any repair instructions out there for it? Any advice all?

Thank you in advanced
Steve