If you have access to a cutoff wheel or sawzall it will help a lot with cutting off the stock exhaust system. A hacksaw will work but your arms will hate you.
As far as the header just take your time. The stock heatshield can be a bitch to get off. I ended up cutting mine out. Then just be sure to clean the header off once its installed with some wipes or a cleaner before you start it up. If you don't your fingerprints will bake on and you will never get em off.