i ordered mine pre-cut off ebay and put them on within a half hour. it's not hard but I'm more of a DIY guy in the first place. The back window can be a little tricky depending on the curvature.
I've done a couple of my friends cars, I guess I learn quick.
i got 5% all around, only had to take them off once cuz I got caught speeding so officer let me go off that but (in exchange) I had to get rid of the tints. I just put new ones on a few days later.
Around here you can only have 35%
by law. But everyone and I mean everyone has lower than that. Luckily tints are not on the priority list for law enforcement in my state.