While this written with the BFP as an example. Essentially the same steps are used for both probes.
Gather Up all the materials. Test fit the pin ensure it is not binding or to tight. it should slide easily in and out without binding.
Strip a length of wire and thread through the hole in the pin.
Flip the wire over towards the opposite side of the pin, the back of the D shape must be facing the back of the probe when assembled.
You want a single twist of wire. NOT TO MUCH this will cause issues if you leave to much here. Trim the excess. Twist the two wires well , so that they are straight on the bottom part that will touch the screw.
If you have issues with the fit you can strip the wire completely bare (it slides much better that way).
Insert the magnet in the top of the pin. Ensure that the magnet will be repelled buy the magnet on top, use the image below as reference. This does not need to be crunched down. It is not designed to be tight. If you have issues with it slipping use a drop of glue. There does not need to be contact between the wire and the magnet. But contact will not hurt it either.
Run the wire up the hole a tiny bend at the end may be useful.
Pull the wire as you continue to insert it until it is fully seated.
Finally strip the end if it is not bare and lay under the magnet and insert your magnet.
Strip a piece of wire and thread from the top down and out the front of the body. This piece of wire cannot be bare.
slot the wire into the screw hole on the front of the body.
start the srew into the hole.
cut and strip the wire on the top to sit under the second magnet on top.
Press the magnet down on top. And finish screwing the contact screw all the way in.
Press in the rear magnet and enjoy your self built switch.