Originally Posted by WEG Cory

I am very lucky, I have Canon Headquarters down the street from our Irvine offices, they do it for free.

Do not try to do it yourself, find a place that offers a warranty on their work.

Also, dust will build up on your mirror, it is only natural, however you can prevent it from building up too fast by making sure you don't change lenses, cards and batteries outside. I take a lot of beach shots, I constantly have dust issues, it isn't a big deal.