Far easier for everyone involved if you just find a used TiVo with a lifetime subscription for sale.
Open Google and use this search string
site:craigslist.org /sys OR /ele tivo
If you find one you like, email the seller and ask if they'll accept payment via PayPal, including the cost of mailing it to you.
Before you make the purchase, get the seller to give you the TiVo Service Number and check with TiVo to be sure it does have a Lifetime.