I would boil it. If you are using hops, you will need a wort to boil the hops in.
But ....... if you want, you can just dump it in the fermenter with the apple juice. Just make sure you sanitize the top of the can and the can opener. You can use boiling water to sanitize both. Pour some boiling water into the 'empty' can to get the last of the extract out.
....... I did the same recently. I was given an old can of Mr. Beer hopped Malt Extract. Used it without boiling with 2 gallons of juice in a 2.5 gallon batch. Figured it already had the hops in it. Have the first bottle in the freezer cooling right now.