I was wondering what is an easy and safe way to remove vacuum lines? Some are just stuck really tight on there. I was thinking of getting a box cutter or razer blade and slicing it off as to avoid breaking the nipples.

 

I will often use a spark plug boot puller tool. Makes life easy. You could always cut the hose off if you don't plan on reusing it.

 

I usually put a good set of pliers on it that have good sharp notches and grip the hose and twist clockwise and counterclockwise then once it breaks free you pull backwards