Motorized or manual?
They really aren't hard to install, though having a friend to help is a huge plus. Anchoring the main components (roller tube at top and arms at bottom (if any) is the only real concern and if you use the same places as your current awning it makes the task simple. Of course, that assumes the holes line at and THAT presumes replacing with the same make & model.
Do you have any complaints about the operation of your previous awning? If so, you can look for a model that has a different characteristic. If you don't, why not stick with the model you have?