1. Make sure your home wave is the current wave and do a page reload.
2. Click the 'Share' button
3. Go to 'Your Wave Admin' tab
4. Click 'Load'
5. Double click the name of the user you want to remove. Drag the name to the 'Remove members' box
6. Click the 'Remove Members' radio button
7. Click the 'Save' button. The user has been removed from your wave.