I watched a gazillion videos on installing this type of product. I made sure I had sharp scissors and a brand new knife type cutter and a ruler. 
I found this product to be easy to use. It is easy to reposition them, as advertised. 
I am thrilled with how this turned out.
I would say from start to finish— it took me three hours or so. It is a small space.

I also used the square footage tool on the website and then ordered one extra package. Just in case.

They look amazing on the wall and I am thrilled with how they jazzed up my kitchen.

I own — so I am not worried about the paint. If you rent— just know… while they are removable… they could damage the paint, the folks who painted here used the cheapest paint possible and when I repositioned a section— it did mess up the paint a tab. So just know… the paint may need touched up, if you remove this product.