I'm looking at buying and installing a Roof visor/outside sun visor on my 59 from LMC trucks. My question to anybody who has installed one of these is what is the difficultly meter on installing one of these. It seems pretty straight forward but is it? How many screws holds it on? Does the windshield get in the way when you have to drill the holes? Any tips, tricks that can be shared would be appreciated.Thanks everybody.......JOSH