Update VUMAT from 6.9-1 to 6.13 or more recent Abaqus versions

As in the title.
I recovered an old VUMAT subroutine that was developed in Abaqus 6.9-1 and I would like to update it to the most recent versions of Abaqus (preferably 2016-4).
Is there some sort of guides to do it?

Many thanks!