You need to use MonacorPG-204P and PG-203P or compatible TRS connectors (2 solder lugs and a big tab for the sleeve connection). Adafruit products 1800 and 1798 are confirmed to work as well.
Cut the 2.5mm and 3.5mm TRS sleeve tab where the hole is located
Put both TRS connectors into the 3d-printed solder guide (or a cheap HT that you don’t mind potentially damaging). Make sure, that they are seated all the way in. If the holes in the solder guide are too small, you can ream them using a 2.5mm and 3.5mm drill bit.
Insert the AIOC PCB into the solder guide
Solder sleeve tab on the back side for both TRS connectors first
Turn around PCB and solder remaining solder lugs
Optionally you can 3D print a case for your AIOC. This model has been designed by a third party but is confirmed to work with the AIOC.