I tried searching but no answer to this one. My car squeal for a second on startup and a notice my idler pully wobbles a little. Is the idler pully replaced simply by loosening tensioner, unbolting it and pulling it off and replacing or is there more involved.

 

Unless you are supercharged, you probably mean the tensioner pulley. It is NOT supposed to wobble, the center axis locking nut is loose. Do NOT drive it until you retighten it (and you probably need to check for belt condition and tension).