If you installed Block Sender on Google Chrome, here are the steps to delete Block Sender.
1) Click the Menu button
2) Select “Tools” and then “Extensions”
3) Click the Trash icon next to Block Sender
4) Press Remove to confirm
If you still need help, please see the “Uninstalling Extensions” support article available for Google Chrome.
1) Click the Menu Button in Firefox
2) Click “Add-ons”
3) Open the “Extensions or Appearance” panel
4) Click Disable next to Block Sender
For more assistance with Firefox, please see the Disable or Remove Add-ons article in Firefox.