It is very difficult to change oneself because once man's mind set itself to some program, then it adapts itself to that program. Once a program is set then it becomes very difficult to change because mind has to work very hard for a change. It requires a lot of energy and efforts to reprogram hence, mind resists change and try to stick to the old program. Therefor, man sees easier to change others as it suits his program that runs his mind.
Only a few determined persons can change themselves. We call them great personalities. Buddha, Mahavira, Jesus, Gandhi, Einstein etc were such personalities who could change their program which they received from their families, societies and socio-political system.