To kill 682 put him in a vehicle with Dr. Gerald because Gerald will somehow manage to kill it.
It won't.
It's pretty much the process at the site, if you come up with a possible way to kill 682, you must also describe how it fails to do so.
For example, here's one of the termination attempts, taken from the SCP site.
"Item:
SCP-826, equipped with one (1) copy of "The Generally Nice, Friendly Thing That Can And Will Kill SCP-682 Permanently if it So Much As Spots That Damn Lizard", a 12-page short story written by Dr. ██████, detailing a large, friendly monster that is stated to be capable of permanently killing SCP-682, and 1 (one) D-Class personnel (D-682-32) equipped with 1 (one) 2010 Ducati Multistrada motorcycle for the purpose of evading SCP-682.
Tissue Test Record:
N/A
Termination Test Record:
Story is put between SCP-826, and placed into large, empty room ██m X ██m X ██m in dimension, with a remotely operated doorway large enough to send SCP-682 through. SCP-682 is brought in front of the entryway securely. Once researchers clear the area, door is remotely opened, exposing a green pasture similar to the one described in the story. SCP-682 is reluctant to go through, so D-682-32 is sent through as "Bait". 682 follows through doorway, whereupon the doorway closes behind them. 30 minutes later, SCP-682 bursts back through the door it was sent through, somewhat worse for wear, killing ██ researchers and ██ agents in the process. Recovery personnel describe the story's pasture as having become a "Battleground", featuring impact craters with enormous body parts scattered around. Parts are thought to be from the story's "Thing". Recovered story is retitled "The Generally Nice, Friendly Thing That Tried To Kill SCP-682 Permanently But Failed" , and is noticeably thicker, with 209 individual pages that detail an epic battle between the two monsters.
Additional attempts to coax SCP-682 into SCP-826 have been met with non-compliance on SCP-682's part."
682 literally cannot be killed by anything. The most you can do is contain it. Put it in a vehicle with Gerald, it'll survive somehow.