What document is necessary for a Bolivian national currently in Bolivia to renew a visa for travel to the US?
You'll need (full list here):
You can apply online or by mail and they recommend applying at least 45 days before your stay expires.
Note your current visa must be still valid otherwise you need to apply for a new one, quoting CIS:
If you want to extend your stay in the United States, you must file a request with U.S. Citizenship and Immigration Services (USCIS) on the Form I-539, Application to Extend/Change Nonimmigrant Status before your authorized stay expires. [...]
You may apply to extend your stay if:
- You were lawfully admitted into the United States with a nonimmigrant visa
- Your nonimmigrant visa status remains valid
- You have not committed any crimes that make you ineligible for a visa You have not violated the conditions of your admission
- Your passport is valid and will remain valid for the duration of your stay