How to Delete a Modifier?

I try to delete them from the outliner with no success
there is no X near any Modifier i add?

I’m not sure for the Dynamic paint modifier, but the collision modifier can be removed through the Physics panel.

thanks
its the first time i see the Physics panel !

and i delete the modifiers

http://4.bp.blogspot.com/-NRxeduv6FAY/T6t3htKwxzI/AAAAAAAAAcA/x0ti-qgP3iE/s1600/Image3.png