i have an 06 uplander 3.5L that i'm trying to change the plugs on, my only question is how do i get to the 3 on the back side of the engine???

You must unbolt the engine mounts and have someone help you lean the engine forward.

unbolt the top mounts and push the car backwards, this will roll the motor forward slightly..be sure someone is inside to set the brake before you stick your arm back there..good luck!