98 Mercury Sable PCM Problem

I had a code kick out p0443. I was told that my car has a perge Valve problem so I replaced it. The engin light stayed on. Then I was told that the problem had to be the PCM. I want to replace the PCM and I can get to the part however, I was wondering if this is a job that should be done by the dealer or is it not a big deal to do by your-self.