When you're at Tivo Central, can you use the arrow key(s) on the remote to move up and down the list of choices?
If so, go down to messages and settings (or whatever your's calls it) and then either push the "Select" button, or push the 4-way arrow key thing, but not directly on the right arrow, but slightly above it, like not at the 3 o'clock position but halfway back up towards the 2 o'clock position.
Or, depending on your remote, maybe slightly lower than the 3 o'clock position.