My parents got green card last year and they got extension for 2 years. We notice that my mothers bithdate is wrong in travel document. It is mention 45 birth year instead 46.
How to rectify the date in extension doc?

They left USA Dec 4th after we got the extension.

Do you recommend them to come back and file for extension again for safer side? They are due to come Jan 2018(extension expires)

Thank you in advance.