As said those Homelite style heads push nuts has to be levered out or cut. What I use now is a modified small flat tip screwdriver that bent into a semi circle ( around 90 degree arc) as to slip under the nut to get to the catch fingers and lift them up as I go around the push nut so I can save the nut for reuse. Once you get it off then you can remove the adapter if needed just note that many of these are NLA separately. Replacement of the same style usually have a new push nut in the packaging or at least it is that way here.
I even use the same style tool to get the push nuts on the MTD front spindle axles off
