Removing and adding players in your pairings is very easy. To do this:
Go to Rounds > Edit Existing Pairings
Click "remove players" in the set of grey boxes in the bottom left hand corner of the page
Click on the players you would like removed (it can be one player or multiple)
You will see the players being removed from the edit existing pairings page.
Save your pairings.
See sequence below as two players are removed from the pairings.
How to add players to the pairings page:
In the Round > Edit Existing Pairings
Click "Add Players" in the set of grey boxes in the bottom left hand corner of the page
Select the players you would like added (if they are part of your player roster and not part of the pairings they will appear in the dropdown menu) If you need to add a new golfer - click "new golfer" - enter the golfers information - then click an empty space in the pairings to add them.
Save your pairings.
See sequence below.