To block beds, you can simply select beds on Bed View with your mouse, right-click the selected beds and choose Block Beds option:
To unblock beds, you can simply select block beds with mouse, use the right-click to show the menu and select Unblock Beds.
If you click on one bed only, you will see two options: one to unblock only this one bed and second, to unblock all previously blocked beds.
If you want to block more beds, it is straightforward when you click the red icon on top of the Bed View to access the Block & Unblock Beds window. You can select the days, rooms, and beds and run the BLOCK or UNBLOCK command.