Try looking up "Perry" that's tends to be the term for pear cider, though many sites have both names on it . Otherwise, look up how to make a hard cider from whole apples, and the process is said to be the same.
Granted, I don't have a press, so I can't juice any of my own fruits yet so take my words with a grain of salt. I just like to research and talk.
Generally speaking, you'll be pressing the pears for juice, like you would apples. Usually grinding them up then pressing them through a press. Some people seem to mention using a larger mesh, or mention they've had the bag kinda filled and that the pears clogged it up a bit. http://woodlandantics.wordpress.com/2010/11/08/pressing-pears/
The rest seems to be like cider.
Pectic enzyme to help clear the pectin.
Take a measurement for gravity.
Add this and yeast (or wild yeast and anything else desired) to a fermenter.
Possibly rack and age, or do a sweet perry like you would a sweet cider per the stickys.