In the Overview screen, select the entity.
You will see a link underneath the selected entity to remove it.

After removing an entity, you should get a message in red that it has been removed.

If the remove entity is greyed out, it means other entities are connected to this entity and you first need to remove the entities to the right before you can remove this entity.

However, if you hover your mouse over the entity, you will get a popup about how to forcefully remove the entity and all dependant entities.

Shift click on the greyed out "remove" link to start the delete of multiple entities.
Remeber, this will only delete entities linked to the right.
Entities linked to the left will remain untouched.
You will get 1 warning...

...and 2 confirmations:

The last confirmation will ask if you want to cancel - click Cancel to continue with the delete.