Sync 2 update to v3.8

[Bourne]

Hi all
I am a bit new to this.
I am needing to update the Sync 2 to v3.8.
I have managed to download a file from the internet for the upgrade but not sure if it is compatible or not. The current unit has Navigation available and the "new" K7 maps.
My questions are:
How safe would it be to update using the downloaded file?
Would there be any compatibility issues if it's not an AU file?
Would it require a reprogram using Forscan?

Any help would be greatly appreciated.
Thanks