That all depends on what type of mold you have. If your mold has a place for the weed guard to be inserted, you can pour the head with the weed guard in the mold with the hook. If it has pins, I'd suggest that you put them in the mold, pour the head then take the pins out. If you don't have a weed guard slot in the mold, you may have to drill the heads to make a hole for the weedguard.
Here is how I do it: I put pins and hooks in my mold, pour the heads, take the pins out and trim the heads.
I use powder paint so I reheat the heads then paint them. Some of the paint gets into the holes so I use a drill and clean out the holes.
Next I put on the skirting material. I do this because I tie my jigs and don't want the weed guard in the way. When the skirt is finished I move to the last step.
Put a drop of super glue gel into the hole and insert the weed guard. Press it into place, lay it down and do another one. In a very few minutes it is ready to go. You could use epoxy but it would take hours to dry.
Be sure you get the right size weed guard they come in fg9, fg12, fg30, fg40 and probably some others sizes I haven't used.