In order to remove athletic opponents and venues, they must be deleted from the game they were added to.

Athletic opponents can be removed by Platform Managers by going to:
  1. Navigate to Extracurricular > Athletics > Athletics setup
  2. Select Manage opponents
  3. Click the delete icon to the right of each opponent
If the delete icon is not there and it shows as a lock instead, this means the opponent is still tied to a game(s). In order to remove them from the game(s), you will need to navigate to:
  1. Extracurricular 
  2. Select Group Finder
  3. Search for the appropriate athletic group
  4. Select the Schedule tab
  5. Find the game(s) with this opponent and click the edit pencil icon
  6. Click the delete icon next to the opponent
User-added image

Next, go back to Athletics > Athletics setup > Manage opponents and click the delete icon next to the opponent to remove them.

The same thing will need to be done for venues, but after they are removed from the game, they will be deleted under:
  1. Extracurricular > Athletics > Athletic setup
  2. Select Athletic venues
  3. Change filters
  4. View