To remove a competency mapping you first need to access the Competency Mapping Link on the Left Navigation Bar. 
You will need to click on Administration and select the Competency Mappings. 

When you are on the Competency Mappings Page, you will need to select a department and course you want to remove Competency Mappings from. 
It will come up with a list of courses which you can remove from mapping. You will need to click on the Remove Mappings button. 

It will then prompt a confirmation warning to delete a mapping. 
Click NO to abort or DELETE to confirm.