Era 100s as surrounds but also as group members

I have a Beam Gen 2 plus mini sub. I have just bought two Era 100s. I want to use them as surrounds (have done that). During the setup I said yes to stereo pairing, but that’s not in fact what I want.  I want the 100s as separate speakers in a group with the Beam, all playing the same full stereo music (for max volume in party situation).  Do I need to undo the stereo pairing before grouping the speakers by playing music on the Beam and holding down the play/pause button on each 100?  If so how do I do that?  Once done how easy will it be to switch between surround mode and grouped?