I don't have a wireless Joey but I assume the instructions should be similar to a Joey3.
To change name on a Joey3
1) Hit the Home key 3 times to get to the diagnostics page.
2) Select Whole Home from the list on the left.
3) Select Change Name
4) From the drop down list you have a whole bunch of choices.
Basement, Bathroom, Bedroom 1, Bedroom 2, Den, Dining Room, Exercise Room, Family Room, Game Room, Garage, Great Room, Guest Room, Home Bar, Home Theater, Kids Room 1, kids room 2, kids room 3, Kitchen, Living Room 1, living room 2, Master bedroom, Media room, Office, Patio, Sunroom, or you can Enter name.