Select the herd from the list or on the map

Click "move"

Change the move date and time to when they were removed from their last grazing location

Click "move" - your herd history will then show your herd as having no location and no longer show on the map.

Select the herd from the list or on the map

Tap "move"

Change the move date and time to when they were removed from their last grazing location

Tap on the field they are currently grazing in

Click "save"