i work fitting screens come across this all the time.
as said put nut back on a few threads:thumbup tighten puller as tight as poss soak in some fliuid and where the wiper arm bends tap it with a rubber hammer should do the trick:thumbup:
i bought what i thought was a full set of green hard handle picks but it had 2 straight ones in the pack so if any one has the 90 degree one for sale
or i could swap for the green straight or a cherry/burgandy hook one
cheers:)