In particular the transfer ownership section. The duplicate and delete will be covered in the next section of the guide.
Transferring a project is useful when you want to start a new billing cycle under a different account. In this case you can go ahead and click "Transfer".
This will let you input the email address of the destination account.
Conversely, the receiving account will receive an email and find a popup at the top of their dashboard:
On accepting the project you'll be charged for the extra project if you are exceeding the limits of the free "Developer" plan.
If the former owner is left with any unused credit it will show in their billing profile and those will be used automatically on any new invoice.
Credit cannot be transferred from one billing profile to another.
If you don't need to start a new billing cycle, as for example you need to change ownership of the project inside the same company, you don't need to use the project transfer feature.
The best way to achieve this is by simply changing the email address of the account owner.
If the destination email is already a DatoCMS user, the destination account needs to change email address too, or delete the account first as email cannot be duplicated.