As jigfinder says "You can do it yourself" but let me give you a few words of advice.
If you are not very electrically inclined you might want to take it somewhere, you will have to either disconnect the wires in the head or at the motor,and some of the motors are sealed and require additional work to reseal them so theres no leaks which would fry it almost immediatly. When removeing the head on handle cotrolled TM - some of them require you to remove a pin in the handle that attaches a stator that tells the motor how fast to turn - make sure that you mark it where its at befor removing or your motor will not run right or lose power.
I think I would look at either trying to raise the motor up on the mounting bracket or another way, alot of them have adjustable shafts to.