Go down to Lowes (or wherever).
Buy this:
https://www.lowes.com/pd/B-K-1-2-in-...ing/1000505043
https://www.lowes.com/pd/EZ-FLO-1-2-...ing/1000365035
You may be able to get the tubing by-the-foot.
Put the tubing on the barb.
Screw in the male adapter.
Stick the other end of the tubing in the antifreeze jug
Open the isolation valve
Start the pump
Antifreeze flows into the discharge header and Bob's your Uncle - you're winterizing.