1. From Setup, enter Permission Sets in the Quick Find box, then select Permission Sets.
2. Select a permission set.
3. Click Visualforce Page Access.
4. Click Edit.
5. Select the Visualforce pages that you want to enable from the Available Visualforce Pages list and click Add, or select the Visualforce pages that you want to disable from the Enabled Visualforce Pages list and click Remove.
6. Click Save.