on most laptops, it's a case of removing a few little rubber nipples around the screen and then pulling out a couple of cables to do a very simple straight replace. I've not taken on the 1521 dell rigs apare, but most are desinged in a way to allow easy replacement of parts. If it's broken already, investigate the screws neeed, and find there is only two little cables that slot into the screen. Dead easy to replace, if you can source the right replacement.
DT.