how to buy a bike from a stranger with money owed on it?

i got this bill of sale below, a signed title, 2 keys, manuals, a video of me paying it off and a video explaining that i paid the bike off and saying he will deliver lien release to me when received… even still have the dudes license lol, but i dont wanna be like nah ur not getting it back until u get the release bc it might make em mad haha

im pretty sure even if he was a douche and didnt ever give me the release i could still reg, insure and drive the bike without it being repo’d, itd just be hard to sell bc of the lien…