I always cut the comb out of the frame to crush and strain it. With wax foundation, the comb incorporates the wax in the center of the comb. It only takes a second to cut it out and then crushing it is really easy. Put the frames back into the hive for the bees to clean up. At some times of year (probably not now) they will also immediately draw new wax.
I've got a video on how to crush and strain
on my blog.
If you are only doing a couple of frames, you can either strain through a fine mesh strainer into a bucket and then bottle it or do a bottle to bottle method - only works dependably if you use a tea strainer between the two bottles. Here's a post
on that as well.
Linda T in Atlanta