I cut the pcb just above the bottom of the zig zag pcb antenna, remove the copper going from the signal line and ground, then scap the soldermask off near the passives, that is also a grounded point.

On the revers side scrape off the soldermask where the ground pins will sit then solder it up the connector doesn't fit the width of the pcb, you can wedge the pcb material you cut off earlier if you want to make the connector stay while soldering.(friction fit)

Here is the end result with an antenna salvaged from an old router.

Also some video of testing the mod and some explaining.

Another version with just a bit of wire.