1. Go into finder 2. On the left there is a tab named applications (should be 4th one down) 3. Drag and drop the Selfcontrol application into your trash bin.
First, wait for your current running block to expire. After the block has ended, just quit the SelfControl app and drag it to the trash , and you're done.
SelfControl is a free Mac app that helps you avoid distracting websites. Block your own access to websites or mail servers for a pre-set length of time.