Blower Motor Replacement.
 

1976 F150 with AC need to replace blower motor.
Need advise on how to do job.
Is this a simple fix or a real head ache.
Is all the work done from under the dash. I do not see the blower motor or mounting fasteners on the firewall.

Thanks for the help

All work is done under the dash, Do a search this Question has been addressed many times in the Past and there is detailed instructions in the past posts.