If you'd rather watch a video on the process I've found this good instructional video:https://youtu.be/EMf9_44BBB8
Go to classroom.google.com and sign in with your old account, apps.atlantic.academy
Find your classroom that you want to copy, go into it and under the people tab, invite your new atlanticacademy.uk account as a teacher
Top right, click your account icon, and
Change account to atlanticacademy.uk
Click the Accept Button on the class, this will now load into the classroom
Go back to the dashboard by opening the menu on the top left and click classrooms
2. Click the Menu button on the classroom and click ' Copy'
3. On the following menu rename the classroom appropriately, 'History resources' for example.
4. Click Copy
This may take some time depending on the size of the classroom. Refresh the page after a few minutes to see if its done.
Click the Menu button on the original classroom that you shared with yourself, and click leave.
Go to drive.google.com and find your 'Classroom' folder.
Right Click and Download on the classroom that you want to save all the documents for.
On your PC you will need to extract the zip file
In downloads, right click the file and select 'extract all',
Tick the 'Show extracted files when complete' checkbox
Click extract.
See Step 2 above to change to your atlanticacademy.uk account
In google drive Open the folder you wish to organise the saved files to.
Click and drag from the windows file explorer window, into the google drive space