Test and find the + and - on the DC Fan wire. Wire it to the connector like shown below. Add 4 small dabs of hotglue at the areas circled in blue. Place the Plug support (Yellow circled).
Attach the Bottom case like this then knock it in lightly with a hammer.
tried a few attempts with many issues with supports, and finish after support removal. Nothing came off clean. Was able to return fan so that was positive.