Well it looks really easy, like they are all on a coil...i believe the one on my 3rd cylinder has gone bad. do they just drop in the hole and then you stick it to the coil with the o ring. or is there a process for doing it.

 

pull the fuel rail up and wiggle the injector out of the side that stayed in. Use a little grease on the o ring and wiggle the new one in. What makes you think you have a bad injector? they rarely fail. I'd swap it with another cylinder first and make sure its bad.