Formal:
* Revise: This implies making changes to improve or correct something.
* Redraft: This emphasizes the act of writing something again from scratch.
* Rephrase: This suggests changing the wording while keeping the meaning the same.
* Amend: This suggests making minor changes to improve accuracy or clarity.
* Edit: This focuses on correcting errors and refining the language.
Informal:
* Do over: This is a casual way to say "rewrite."
* Start over: This implies beginning again from the beginning.
* Redo: This is a simple and direct way to say "rewrite."
* Fix up: This suggests making changes to improve something that is not quite right.
The best synonym for "rewrite" will depend on the specific context and the type of changes you are making.