Rv roof vent and shower dome replacement

That time of year. Opening up the rv and figured this would be the year I replace the bathroom vent so the fan works and replace the shower dome. What troubles should I look out for? Any recommended parts? Eternabond roof tape to complete the job? Anyone ever done this job yet? Any help is appreciated. 2000 rock wood Roo. Phone Post 3.0

Here is a YouTube video. I didn't watch this video so yours may be different but there were a ton that came up in the search.

http://youtu.be/ZfeBaEazpBA Phone Post 3.0

Barbasol - Here is a YouTube video. I didn't watch this video so yours may be different but there were a ton that came up in the search.

http://youtu.be/ZfeBaEazpBA Phone Post 3.0
Thanks. Love the shave cream by the way Phone Post 3.0