Formal/Technical:
* Paraphrase: To express the same meaning in different words.
* Restate: To say something again in a different way.
* Rephrase: To phrase something again in a different way.
Informal:
* Substitute: To replace one word with another.
* Replace: Similar to substitute, but can imply a more permanent change.
* Reword: To put something into different words.
* Say the same thing differently: A more colloquial way to express the idea.
The best verb to use will depend on the specific situation and what you want to emphasize.