Ooh...it's been a long time since I've replaced a pair of hinges on a laptop !
Generally not a particularly pleasant task, although the worst bit tends to be the fiddly display ribbon and power connectors.
If you can, get hold of the service manual for your laptop. That will stop you disassembling more of it than you need to, and provide guidance in the right direction.
Otherwise, maybe a poke around youtube, sometimes kind souls have made short films showing what needs to be done.
Don't forget anti-static precautions !
P.S. Have a suitable set of containers at your disposal for storing screws etc.... and take your time, don't rush it and don't force anything !