If you want to add/remove a block of content on the left side of a specific page, here is the trick:
- Edit the page
- Click on the "Outputs" sub-tab
- Find the region named "LEFT-COLUMN-BLOCK"
- To remove the block, either click on the red circle next to the block or check the "No Block" checkbox on the far left
- To add the block, click the region's block icon or  and browse to your custom block of content
- Submit the change and publish
* Note: If you want to add social media links in the left column, use the simple built-in Social Media Buttons technique.