roof panel replacment

Has anyone out there replaced a roof panel before? My current duster project has a dented roof someone was likely standing or sitting on it.

I have a nice roof panel I could use. How difficult is it to change out the roof skin? It looks like there are spot welds around the drip trough and under the chrome windshield and rear window trim. The a and b pillar might be a little tricky too. Other than that it doesn't appear to be too difficult. Anyone done this before?