Here's the boot floor parts removed, the rear is to the right.
The plastic tie downs are secured with 2 rivets each, once removed this section below can be separated from the base. I've rotated it around to show the reverse side where you plan to fit the tracks.
Close up. It's about 30mm thick.
The base section.
Close up. This is where the tie downs secure to through the carpeted part.
Close up of same area reversed.
Wide shot.
Hope this helps, I've removed these parts to install a more secure floor with a plan to mount a fridge slide and drawers. This is also freeing up 140mm of underfloor space, thinking to put a compressor and water bladder under there.
Edit: The space created under the boot floor is now closer to 120mm since replacing the plastic with a carpeted sheet of 15mm ply.
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2010 KK Sport, LPG, Mygig, Uconnect, JBA UCAs, 3" CRDstu lift & Uneek bull bar.