FYI: That exhaust can be a bit loud because the sound is reflected off of the ground back into the cab.
Instructions: http://www.magnaflow.com/07techtips/pdfs/17147.pdf
You can also set up a mod meet if you need help. TW has many more active members though.
Flowmaster mufflers make for a raspy sound which, in my opinion, sounds like trash and the chambered design adds restriction(fact). They are popular because they are cheap.