Looks like you might have just enough room with a hooked pick to pull out old packing but looking at the condition of things in those pics I would consider pulling the shaft and replacing everything with new.Ijust replaced my trans.and found packing nut worn on one side from miss alignment and shaft worn at packing location from over tightening by PO, non of the work was a picinic but I have peace of mind knowing all is well.This turned into more of a project than I wanted but for $500 and one weekend of time it was well worth it.