I wouldnt say it is hard. But if you have never done it before it can be time consuming.
A tech can come in and be gone in an hour. Motor is usually on the truck, they do a lot of them thus have a system.
For a homeowner, just make sure you leave 3 hours you can have the unit down and take your time, write down what goes where or take pictures.
The hardest part is commonly getting the blower wheel off the blower shaft.