I assume you have already done a proper Forum Search for your model number in case other people have already answered your question ?
If so and that didn't help then check out this thread: https://community.sling.com/message/10363#10363
Come back if it that doesn't help either.
Hi Gonzoshine, I hope this works for you.
As stated by the user gpk1 in another post, give it a try with TiVo Premiere, if it doesnt work (which didn't for me), try TiVo Default (Remote Address 1) -> This one worked for me.
Here the configuration I used:
Cable TV Box > TiVo > Default (Remote Address 1).
Have a good day!