I'll use this post to make a wiki about extracting the motherboard of the controller.
first, remove this 2 screws
in the bottom there are two crosshead screws that in the photo I already removed

go back and remove all screws
take a screwdriver or something of similar and begin to remove the liquid rubber that seals the hole where pass all cables. I suggest to remove it well otherwise the cables will not pass.
It's better to remove cables one at a time. I removed the battery cable to last.
Now the controller is free.
Remove in the side of the controller the screw that hold the sensor (this photo is on loan eheh)
Now it's better to use a tool of plastic or a piece of wood to remove part of sealant.
Remove well the sealant that cover the mosfets and a screw in the bottom. This photo is for reference.

Now with a tool pass it all arond the controller. It goes well a ice cream stick.
This part is invasive.
take a hacksaw, or a dremel, it's better a hacksaw because you have more control.
cut part of the shield. do not cut at the height of the mosfets because it is a bit more difficult to cut and to remove the board. it is better to cut lower.
The side to cut is opposite to the one where the sensor was screwed in. So you have an access to the lower side.

With pacience, leverage with a tool to lift the block of sealant. Don't damage it, just detach it. it will come away whole.