Yeah, as said, no pellet gun with be quick and human. .22 might depending on the shot.
1) Get some fruit, apples tend to work.
2) Poke holes with screwdriver, knife, pen, etc.
3) Soke for a couple of hours in antifreeze.
4) Set out and let a skunk win a Darwin award.
5) No clue on removal so...good luck with this step.
6) Profit.
Oh....if you have any pets or kids that would eat poisoned apples this may not work.