How can I fix my Nissan Micra heater blower?

The blower on my heater in my 1999 micra is not working and am not 100% sure whether there is any heat coming out either.

Do you think it is a resistor or new motor that I need.

I have been told that the new motor bought new is very expensive but the fitting is easy.

I wondered if I bought the motor from say ebay, how hard it would be to fit myself?

Does anyone know?

Many thanks

N