Basics I can give....
CNC Freeze-off or PB Blaster...that is your friend. Good idea to have a breaker bar handy just in case.
The heat shield has 10 or so bolts, some of them hidden. My replacement GS one has 3 lol.
the stock DP has a hidden bolt 1/2 way between the turbo and the bend at the bottom. Your aftermarket will not have that.