To Block Beds you can simply select beds on Bed View, right click the selected beds and click on Block Beds:

To Unblock Beds you can simply click on blocked bed and select the option to Unblock All or Unblock Selected Night:

If you want to block more beds, it is very easy 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 BLOCK or UNBLOCK command. 

See also: How to Block / Unblock entire room or day