I can't do it this way. The way you described, was how it used to work before this update.
Currently, I have this:
Old show, my wife recorded "The Assassination of Gianni Versace" She watched and deleted the episodes as she watched them. However when I go to Series Manager, the series is still listed. I can change the priority of the series and put it at the end of the list, #98. I can't delete the series. The only option I have when I highlight the series, is to Cancel Upcoming recordings (there are none) or press 1 to Move to Top, make it the highest priority. Even clicking the red button for a normal deletion just gives me the tone, and nothing happens.
I have one opening for recording another series, max is 99. At this time I'm not willing to try to add an extra one to see if I can force a deletion, in case a new show pops up that I want to record. This what was I described when I talked to customer no-service. He told me that they were aware and eventually would fix this, maybe.