I have a 87 cherokee and i know nothing about cars or anything im use to putting water in the radiator by opening the cap on the radiator on this vehicle there isnt one to add water do i put it in the little resovor thats mounted on the pass. side firewall and whats the proper way to fil it up

 

Yes it is, I would do a search on closed cooling systems here so you can get familar with this system.