If you have more than one project you have the ability to move data items between projects in your account. You can do this by opening the data item in the editor and clicking the move button. You will then see a dropdown menu of all your projects. Then simply select the project you’d like to move the data item to. 

If you are looking to move an entire project to another account (ex. a client wants to take over their project) you will need to reach out to support@schemaapp.com