(0=no pain & 10=worst pain)
Removing the drain usually doesn't hurt at all (1-2 on a 10 point scale). It's completely worth it, if they are indicated for your surgery. They are annoying and most people are so happy to have them removed that they don't even care about the very momentary mild discomfort.
Drain removal should be relatively painless. One trick is to place some antibiotic ointment at the drain skin interface to keep the drain from pulling on the skin when it is removed.