Which is harder to do.. extracting teeth from the top row or bottom? and why?

Lower row: That being said with a good surgeon who has good technique the difference should be minimal. The difference is due to the different types of bone between the upper and lower arches.

Tooth extractions: I have been extracting teeth for over 40 years and personally have found no difference in the difficulty of extracting teeth on the upper jaw vs. the lower jaw. It's more a factor of the size and shape of the roots and the integrity of the tooth. For example, a single rooted tooth, top or bottom is easier to remove than a three rooted molar that is broken down by decay & had root canal therapy.