Formal:
* Enlighten
* Clarify
* Elucidate
* Explain
* Illustrate
* Inform
* Convince
* Persuade
Informal:
* Get across
* Help us grasp
* Show us
* Put it simply
* Break it down
Other:
* Communicate
* Impart
* Convey
* Teach
The best word to use will depend on the specific situation and the tone you want to convey.