You are able to translate the paperwork yourself as long as you certify that you are competent to translate and that the translation is accurate.
From the USCIS website:
"Please submit certified translations for all foreign language documents. The translator must certify that s/he is competent to translate and that the translation is accurate.
The certification format should include the certifier's name, signature, address, and date of certification. A suggested format is:
Certification by Translator
I [typed name], certify that I am fluent (conversant) in the English and [enter appropriate language] languages, and that the above/attached document is an accurate translation of the document attached entitled [enter title of document].
You can find more information here: https://www.uscis.gov/forms/forms-and-fees/general-tips-assembling-applications-mailing