Currently, it is not possible to resubmit the vendor risk assessment once it has submitted by the vendor.

At the time of this writing there isn't a way to resubmit it once the vendor has submitted the assessment. 

Currently, the vendor assessor can view assessment responses after the vendor has submitted an assessment. The vendor assessor can also add comments or change responses, as necessary. 

 

I have raised an Enhancement request FTASK38321 to add this feature to the application.