We dont have shard of adonalsium if we wonted or needed to kill him or just imprison him as how preservation dealt with ruin till vin came to kill him and dont really now much of hoid, but best bet kill kill him could be hemalurgy. Get atium in shape of spear (to get as much of his soul, hopefully getting piece of it that code this healing) in hands of iron inquisitor under direct control of harmony (to have instinctive knowlege of hemalurgic points and precision). Problem is mechanical properties of atium . Its best bet to ge his healing property without guessing what metal to use, but do we have problem as making silver bullets for werewolfs, too soft and easily deformed? Only mention of easly damaged by stomach acid, so mistborn eat it moments before need not still at home before going on assassination knowing it gonna be used i guess if remember correctly. Its used used as spike in lord rulers time to get temporal abilities (seeing future by atium), but it surely different in making spike used on naked, tied target and maybe armored target when it shaped as weapon. It more question if hoid is armored, but even unarmored he has a little hobby of collecting new magical abilities from worlds he visits. Somehow beat him unconscious first i guess. Hoid sad at end of Words of radiance: He looked down as she twisted her Shardblade, rotating the tip, still pointed at him. “I’d be surprised if that little knife of yours poses me any real threat, Kholin. You can keep waving it about if you want, though. Perhaps it makes you feel more important.” And killing method could be needed if well intentioned extremist depending on his goal. Is he said to be important character in sf mistborn 3th trilogy though on what side? And while I am your friend, please understand that our goals do not completely align. You must not trust yourself with me. If I have to watch this world crumble and burn to get what I need, I will do so. With tears, yes, but I would let it happen.
Hoid to dalinar, words of radiance, at time writing his top quote on coppermind wiki on his page.