fuel injectors

Well after months and months of trying to figure out what was wrong with my car, 2 different mechanics, my brother and i have all looked at replaced parts... But any way it ended up being the fuel injectors... the shop wants to charge me 1,350 to change them... Well for 500 bones i can buy the damn things my self.... Ive worked on cars qwite a bit, worked in a body garage welding and pulling cars on a frame machine... ive never changed injectors, dont seem like it would be that hard... pull the upper plentum and there they are with a little retaining clip and a wireing harness.... is there anything special that needs to be done when changeing the injectors that i dont know about... i know i have to change the upper plentum gasket... but anything elsne... This guy took a few too many hits off his crack pipe when he came up with that total...he is a friend though and said he would toe it back too my house so i could do the repair... OR is there something thats gunna make me wish i paid him to do it ?

What year and engine is this?

sorry about that..... 95, 3.1 sedan... just turned 114k, excellent condition.