How do I cancel an MDR reservation

[DanSgt]

Made a reservation for 4 in the Manhattan room, from the NCL app, on a May cruise.  I now wish to change the reservation to a different restaurant and cannot find a way to cancel. Trying to add a new/different reservation just says that I have a conflicting reservation. A catch-22. Please help.

[Sauer-kraut]

 You have to call.   There is really no need to book the MDR in advance.

[Lorey2007]

Just give them a call I needed to change a time, when I called they actually had more times available than what was shown. I know you don't need to make a reservation for MDR but I'm a little OCD and like to plan ahead. 

[DanSgt]

Thank you for the replies. We made reservations only because there are 4 of us in 2 cabins trying to coordinate dinner and making a show on time. Also, this was a port day and there will be many people trying to do the same once back on board. I will call tomorrow.