Pioneer RX2 broken grounding post

Hi, 

I'm having problems with the grounding post on my Pioneer RX2 controller. This happened very soon after buying it. Should have tried to get it fixed under warranty, but didn't get round to it. I think the grounding spindle is way too skinny. Poor design. I must have overtightened the nut or something. Now the spindle seems loose, like the nut on the inside of the controller has come loose. Pretty sure I need to get inside the controller to resolve the issue. Ideally I want to remove the old grounding post/spindle thing and drill a larger hole and install a chunkier bolt in its place.

Has anyone done this before? Is it easy? Are there any security screws or anything else tricky to contend with?

Any videos available on how to take the controller apart?

Thanks in advance.