That I actually learned to do at the vet's office. It's not terribly difficult, but it is terribly yuckie.
One of the perks of being human.

Besides all this wonderful stuff we get to do for all these great babies!!!
Here's a video that shows how to do it that I found on YouTube. It has all the good info and shows how. It is kind of gross, so if stuff makes you weak to your stomach, this video may not be for you!
Also, I think they could have chosen a much better name for the video. Sorry, not my choice.
I wear latex gloves when I do it though and use the paper towels. Just be sure not to squeeze to hard, you don't want to hurt them!