Disney typically does not let you drop days off a reservation like that any more. They do on exception sometimes, but for the last few years it has required complete rebooking.
FWIW, I just did this a couple weeks ago for CBR. I dropped 3 days off the back end.
MDE on my browser was going to let me do it, but it wanted to bump up my room rate. So I had to call so I could keep the old room rate and drop the 3 days.
For that matter, I also dropped a day off the front end but that was before the 60 day point/FP+ window opened. That one I called on also for the same reason - room rate.
When I know the approximate time I will be going to WDW and find a good rate, I typically book extra days on the front end and/or back end to give me some flexibility before locking down my dates. I booked CBR back in October I think. I have a conference in Tampa and I did not know the schedule for the conference (i.e., the specific days I would need to attend). So I booked the extra days at CBR. When the firm conference dates and schedule was announced in December, I dropped a day off the front of CBR. I was aware I could have kept that day until after my 60 days FP window, booked my FPs, and then dropped the day. But like others have said, that is cheating the system and I do not want to do that.
This thread would have affected my business colleague going to the conference. He had his own room at a different WDW hotel, and I thought DS22 was going to come with me so I had my own CBR room for us. I had added my colleague as family & friends so we could get FPs together. When DS22 decided he could not come, and my colleague and I already our FPs, I invited my colleague to stay with me and drop his own room. So he canceled that and I added him to my room reservation. That worked perfectly on MDE but I was concerned his FP would get lost in the mix. It didn't.
I guess with this change in policy in this thread, we would have to call Disney so he would not lose his FPs when canceling a room but switching into my room?
