Copyreader, e.g.

• One changing a bill
• Change maker
• Maker of a change or revision
• Constitution modifier, e.g
• Unexpectedly named by Queen, one changing for the better?
• One improving in the morning, one coming last
• Editor, at times
• Copyreader, e.g

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Amender \A*mend"er\, n. One who amends.