There was a threat started on the old forum about Xiaomi Hacks.
Thanks to @bullseye1977
“Pretty new to all the homey possibilities. What i created is a cheap proof of concept zigbee wall switch.
Bought a “puls drukker” at the local Hornbach and soldered the switch to the internal contacts of the Xiaomi Aqara Smart Wireless Switch. Now i can select 4 scenes with this wall switch (on - off - dim 20% - sexy time) of my phillips Hue / Ikea lighting.
Nice thing it fits my current wall switches and i have one uniform look on the wall.”
There where a lot of people interested in the schema to connect the “puls drukker”.
I’ve take a multimeter and came with this conclusion:
Connect the “puls drukker” on the two holes.
@vaderag Xiaomi / Aqara typically use the same connections to fix the housing parts… 2 sides with 1 clamp and 2 sides with 2 clamps.
If you gently use a sharp knife you can unclamp the clamps at 2-3 positions and then you are able to open the housing
And, presumably, it doesnt matter which way i connect these little holes, just that they are connected, right?
 answering my own question… of course it doesnt.
Just managed to whack it together - my soldering skills are terrible, my soldering iron too big and I nearly de-soldered a piece next to the holes, but it’s working and held together with electrical tape
Can’t get the back on the thing again since i have the wires poking out a hole so the battery is held in with tape too.
Also the actual button seems to be stuck depressed so that a sqeeze of the unit activates it. No idea how that’s happened!
But, it works.
Momentary switch on it’s way so wiring it in when it arrives and I should be in business