Adding others to our Specialty dining reservation

[akowilm]

This year we have invited 6 friends to cruise with us aboard the Reflection. Last year, we enjoyed the ultimate dining package, but decided against that for this cruise because we wanted some of the first timers to experience the MDR. Also, some in the group did not want to add an additional $400 to their cruise budget! My quandary is this: we KNOW we want to have DH's birthday dinner at the Lawn Club on a specific night at a specific time. I plan on booking online soon. The others plan on joining us that night, but want to use their TA issued OBC for this dinner, as well as one we have planned in Murano. How difficult will it be for us to add friends to our existing reservation? Has anyone tried this before? Is it just a matter of getting to the Maitre'd as quickly as possible so the others can book their reservation and then ask to link/dine with us? Any advice is appreciated!