I used a grinder, just grind the bumps inside the bottom of the shelf. Then pop it off. The sparks get a little crazy in there though.
Then I siliconed the little holes left in the side. Just for the heck of it.
When I remounted it I put it higher for more clearance for the T105's.
If your putting in any Trojans on the top shelf maybe it can't be raised too high, but T105's won't go into the bottom with the shelf factory attached. I never really tried to put the batteries on the bottom with the shelf attached, but it sure is a heck of a lot easier with the shelf removed and there would be no way to check the water without pulling out the batteries. Even like I have it it is still difficult.
I only put screws into the sheet metal sides so the heads stick out 1/2" and that's what the shelf sits on. If I was to put a battery up there that would have to change. But it easily holds other stuff.
I put a 1/16" piece of ABS plastic on the bottom over the giant spaces that the batteries slip into and drilled 3 holes. 2 of them should have been over more like the end one, but oh well. Then the underside has screen siliconed to it, to keep out critters.
The back strap clamp is at the top level of the batteries so they can push tight against the wall and strap much tighter.
I don't have genny prep so four small brackets and a 2'x4' table makes a shelf. The white one on top is another 2x4 table that folds, so if I want 2 tables under the awning I can take out the shelf table too. And three levelling boards just incase.