Inside the electronics enclosure of the vcore4, one wire track is replaced by this print, in order to mount this linked power regulator: https://www.amazon.com/Converter-1-25-36V-Voltage-Regulator-Display/dp/B085T73CSD
This mounts in the same way as the original wire track and the linked power regulator comes with it's own hardware for mounting. You will just need to add 4x 3mmx6 socket cap screws.
I replaced the track that runs between the octopus and the pi. I tapped off of the 24v input bed power terminals (not bed output!) on the octopus to power the regulator making the wire run short. I set the output of the regulator to 5v and double checked with a multimeter. I connected the now 5v output of the regulator to the GPIO connector 5v and ground pins on the Pi. 5v is the second pin, and ground is the third, on the outboard most row when counting from the pin closest to the SD card end of the Pi. In the cover photo above, that would be the bottom right hand corner, counting right to left.
The author remixed this model.
Revised wire track in vcore electronics enclosure to add a mount for a small power regulator to power the Pi