There are two different compensation plans, fixed and variable.
Fixed compensation plans
To change the fixed compensation plans, you click on a specific plan and click edit. To change the amount you click in the action pane on compensation structure.
In compensation structure you can do changes on the levels and the amounts.
Variable compensation plans
To change the variable compensation plans, you click on a specific plan and click edit. In edit mode you can do changes to the process, leverage and the level overrides.