First you will go to Menu > Manage > Players/Teams > Teams.
Choose the Division, add the New Team by Clicking on Add team with members.
Fill in Team name, Players under Find Players and Add a Default location.
Or if your team already exists, select the team under: All. And Add to Division.
*Step varies for singles league, few steps below.
Then go to Menu > Manage > Brackets/Round-Robins > Round-Robins.
1. Select the Round-Robin,
2. Click on Replace Team/Player.
3. Choose the Bye to replace.
4. Type in the team name in the Find Team/Player that will replace.
Choose the right team from the drop down list.
Click OK.
Make sure the system was able to fit all the matches to the correct location. You may have to tweak some schedules if it didn't fit.
*For singles league, instead of going to Teams, you do the same thing but you go to Players. Choose division, add player etc.