Thank you for all your advice!
I just got rid of the pads in the living room, sprayed the carpet with a deodorizer, and covered them with boxes.
At my boyfriend's place where I staid with Choco for a month, we had two spots and eventually got rid of one by blocking the spot with boxes until he went straight to the designated spot.
DBlain, thank you for your kind note! Where did you get the litter box?