Attached is a picture of my Pro lite:
This was a very simple yet flexible modification. The black 1.5" tubing is part of an old model 3 post that I cut down and drilled a hole in. In said hole, I placed an old style PRO post clamp (brass insert and Allen key - or Kipp handle - to tighten). This allows the post to extend and contract over the original 1.25" grey PRO battery post. Then I garbed an old monitor arm clamp for a 1.5" post (since all my posts are 2" I had a left over one) and attached it to an Anton Bauer plate. That handled the mechanical sides of the equation. The power side depends on what you want to do with the sled.. This is my light weight sled/backup sled. Most of the time, I'd use it with one or two batteries so for me, it was about shifting the weight of one of the rear batteries forward. So, I use a P-Tap to P-Tap cable to run from the front plate to the now vacant AB rear plate. Simple. If you were to use three batteries on the sled, the front battery would be in parallel with the rear battery that you were connected to via the P-Tap. Another option that would probably be a bit more secure when it comes to power loss would be to use a P-Tap to XLR and then run the XLR into an AB plate that has an XLR receiver. That setup would obviously weigh a little more and frankly, the P-Tap to P-Tap should suffice.