Once the part has printed, clean up all of the edges to avoid any printing artefacts such as blobbing or stringing. Ensure the lid fits snugly onto the case (it should "clip" on and hold itself quite securely, even without the screws). Drill out the two holes in the lid and the case with a 2mm drill bit. After soldering the cable to the back of the connector, lay the cable and connector into the case. Clip on the lid and screw in the two screws, and you're done!