If you want to modify master content only for the current design, you can detach the design from the master. Detaching copies the master content into the design allowing you to make changes, and breaks the connection. Therefore, changes you make to the original master will no longer affect the design.
To detach a design from a master, follow these steps:
1. Open the Inspector.
Double-click the master on the Editor canvas.
2. Detach from master.
Click the Detach Master button. The master content is copied into the design allowing you to make changes. The handle becomes a Container component, and the constituent components are included as children of the Container.
As shown below, you detach a master from the Inspector.