Jim
If you disregard the pin locations shown in the illustration below, the drawing shows the relative position and orientation of the "pigtail" spring inside the cavity of the trigger.
On your particular trigger, (MIM) the short leg of the spring fits into a slot inside the cavity, (use a magnifier) and the log leg is then carefully tensioned and the hand inserted while this tensioning is applied. I use a small pin punch to insert into the cavity and tension the long leg. It will help if you place the trigger upside-down in a padded vise while this hand work is done.
Many here place the assembly inside a clear plastic bag while working, which serves to catch any parts that have a mind to exit the work area into parts unknown.....as they often do.