question on pulleys

So my girlfriend got in an accident in my car(00 Civic-EX), the front end got bent into the AC and alternator pulleys-It didnt do any serious damage(that I know of), but it's making this annoying grinding noise, even after the frame/body work has been done.

Today I had the AC pulley replaced (it was the one making most of the noise) but I am guessing that, in order to get rid of this noise completely, I am gonna need to replace all of them...along with the damn AC compressor, but that's a different issue.

Does anyone know how hard this job will be? I have never replaced any belts by myself and am worried about getting the tension right. The manual makes it seem easy, but whenever I actually get to working on something that seems easy in the manual, it usually turns out to be a pain in the ass. Also, if anyone has any brand recommendations I would appreciate them; right now I'm probably gonna go with AEMs since they were the easiest to find and I probably wouldn't know the difference anyway.

Sorry if i seem like i know nothing about my car; I do, but its really hard to tell exactly where 'grinding' noises are coming from when there's been an accident.
Yes, I know I wasted my money on the AC pulley if im just going to replace it with an AEM.

its easy to tension the belt you just dont want them to tight or they will burn the bearings up in you accesories . usually is leave 1/4 inch of slop int the belt but changing pullies get hard the alternators are a biatch. If you are trying to go performance pully i suggest unorthodox racing