There are two covers on each side of the OBC/Radio console that will need to be removed. They are about 8-9 inches long, these will need to be removed.
I used my finger nail to get into the gap and then just pull, they are pretty durable and just clip in. Once you get these out there will be four screws (2 on each side) that you can remove.
I have only ever gotten to this stage before, because at this stage you will find that the 'cage' that holds the A/C, Radio and OBC is actually seated behind the outer centre console (hard to describe, easy to show) and I didn't feel like ripping out my centre console so I can get a cage out.
I did this when I was replacing my OBC, upgrading it to the full OBC. I'm not sure why you state that there is a lever on the right side of the OBC, it's only on the right side when the car in question is right-hand-drive. For LHD, the lever should be on the left (on the side where the radio is).