If they are in the way or something,or don't produce any pears,,,,,but you can prune them,,if they are healthy,,,don't lob the top off like you see some people do shade trees,,,,,get you a pruning book,,,after you thin one out properly and cut all bad crossed limbs off,it won't look like same tree,,,than,,get you a pole pruner[after reading that book],and cut off upward growing limbs up where you can reach,,which would be maybe 12-14 foot up or so,,,pears grow straight up alot,,just gotta keep up with this by giving them a good pruning every 3-4 years,,you want to shape it too,,,but pear limbs,,wanta grow up[or down],,you gotta try and make it grow side ways,,,thingy