I have finally figured out how to do this.... Sorry JimSpence, but I didn't totally understand your answer.
So, if anyone finds this thread, this is what you need to do. I have one Tivo...
Going into System Info, my remote address was set to "0". With that page up on my TV,
1. I set the switch on my remote to DVR 1,
2. cover the remote with my hand,
3. press and hold Tivo and Pause button at the same time until the red light came on and held steady
4. point remote toward Tivo and press 1
5. press right arrow - at this point, I see the remote address on my system info changes to "1"
Next,
6. Flip DVR swtich to "2"
7. Repeat steps 2. and 3. above
8. **Still holding my hand over the remote**, I pressed 2
9. Hit right arrow
Success! My remote does not work when set to DVR 2, i.e., it's locked.