One fast way to change ownership of files you own on Viking to Enterprise is to use Shared drives.
Click on New+ >> Folder
Give the folder a name and press Create
On the Google Drive side bar, press the down arrow next to shared drives, followed by your new shared drive, and then the folder. This prepares the data transfer process for the next step.
Folders cannot be shared to shared drive at this time.
Select one or multiple files you own in your Viking account, then click and drag it to the Shared Drive. You can choose to use a folder you created, or upload it to the root folder.
You can tell it's the K12 account when you see the HIDOE logo in the top right corner next to your profile photo.