Hi Dee 8080 FIRST pull the power plug.You may need to pull the whole blower makes it easier that should be a few 5/16 sheet metal screws and slid blower assembly out. To slide the motor out you need to loosen the set screws in the middle of the blower wheel that hold the wheel to the motor shaft, might be two set screws,sometimes allens,or square heads. Here is the trick remove set screws all the way put liquid wrench,WD-40,in thread holes. You want to break free the motor shaft from the blower wheel,hang onto motor shaft with a wrench and spin blower with hand,work it back and forth pulling the motor out,reverse actions with new motor.

The motor shaft is not budging I put liquid wrench in the shaft bolt thread hole still nothing

OK I tried everything you said but the shaft is not budging do I have to replace the whole unit