Replacing a cracked Header Panel

I had a small accident last Fall, and I am looking for advice and guidance on one of the repairs that I need to make.

My 2002 Malibu LS was hit by a deer in the right front, and it damaged the fender, fender liner, mirror, and the header panel. I was able to get the fender parts and mirror from the local yard, but I could not find a good header panel.

I've already replaced the fender and mirror, mostly with help from this site, and now I'm looking for information on the header panel.

I've seen on this site, that others have replaced the panel, but without much detail. At Euthymia’s suggestion, I am posting here so that we all may share.

My first question is how difficult is it to take out and install the header panel? Are there any hidden bolts or pins that are covered by other pieces like the fenders or bumper? I’ve read where others have had to remove the bumper, or the hood latch, and others who did not.

My next question is, I’ve seen prices for the header panel anywhere from $50 to $120 plus shipping. Are there places to avoid or does it matter with a plastic part?

My last question is that I am looking for a good service manual that gives specifics on the mechanical and electrical, as well as, the body panels, any recommendations?

Thanks in advance for your help.