Need info on removing wire harness junction block

The one behind the drivers side kick panel. The drivers door wiring harness connects into it via 2 connectors (both blue on my car). Has anyone ever done this? Its not just as simple as undoing the bolt at the bottom. The top of the junction block remains fastened to the car some how and I cant seem to figure out the way its being held in. Please help me out here.

I also want to remove J/B No 1 thats right behind it so I can fix some of the fuse connections. So any information regarding that would be extremely helpfull also.