You enter the project and click on team in the menu to the left in the project view.
Click on the permission that the person you want to delete has.
Search for the person you want to remove from the project.
Click on the name.
Click the green arrow. The person is now removed from the project.
TIP! You can also drag over the names instead of clicking on the green arrow by holding down the name and dragging from the right column to the left.