Changes a grade

• Awards another star to, perhaps
• Gives another star to, perhaps
• Puts into a new category
• Gives a new value to
• Changes a review
• Changes at Standard & Poor's, say
• Downgrades, e.g
• Bumps an R down to a PG-13, perhaps

Wiktionary Word definitions in Wiktionary
vb. (en-third-person singular of: rerate )