Step 1

Very carefully, use the Exacto knife to cut away the chain's collar from his neck. I found the best way to do this is to rotate the head to that the collar is easily accessible. Eventually, you should be able to pull the chain away if the collar is cut enough. I did this four times, and it does get easier.

Step 2--(Optional)

If you only have one of these figures, and would still like to display with the chain, I suggest this. Cut the collar away from the chain about 1/4 up the collar from the chain. This way, you can just insert the remaining piece of the collar under his chin, and it will look the same as it did before you cut the collar away.

Tip provided by:  Darth Bunkaroo Andrew Bunk