I had a skunk get into a trash can that only had a little stuff at the bottom. It got in but couldn't get back out. I took another trash can and carefully set inside the one with the skunk. The skunk can't do anything. Then you can dispatch with it as you choose.
.22 or other small caliber headshot is the only way to go if you choose to shoot it. I took one out with a 12ga a few years ago and the back half of my property smelled HORRIBLE for 2 weeks.