Need help replacing heater/vent blower motor.

it's probably just clogged with debris/insulation, remove and clean it out.

 

they're super easy to remove, underneath the glove box area you'll see the cylindrical-ish looking area and a few bolts/screws holding it in place. you may have to remove the kickpanel if there's a plastic piece there, it's usually just barely clipped in with two plastic pieces that pop out at the top. remove that and you'll have access to the blower motor.

 

they rarely fail so they're only a few dollars used and super easy to replace. unscrew, unplug, replace, done.