On the new Device:
Once you have noted your user information and updated your password go to each group you own and update your Join Code. Also note the code ID and join code so that you can regain control of your groups on your new phone/device.
Once you have updated the Join Codes for all the Groups you created. The next step is to delete the group, but only delete the group locally DO NOT DELETE the group off all devices (if you do the group will be gone and you will need to create a new one).
Once you have completed the steps above and removed all the Groups off your old device just install InnerGroup, use the user information that you noted, re-join all the groups you where a part of (to include the ones you own, and the ones you don't).
As New Phone are sold and you wish to replace your phone and retain control of your Groups here are the steps you should take to properly remove InnerGroup from your old device. The screen shots show iOS but the steps are the same for Android and MacOS.
The First Step is to endure your user information and Update your Password. Click on you user information to Update your password. Do this to ensure that you have the proper user for the new device so that you can gain control of the groups you created.
On The old Device: