If you want to change the roles of the members of the team groups you have, you can usually use the Teams Admin Panel.
In cases where there are too many members in the group you want to change roles, it may not be efficient to do this from the management console, or you may not see the action taken.
The next thing to do is to use Teams Powershell commands.
First of all, we use the get-team cmdlet to see the properties of the group.
Get-Team -DisplayName "Group Name"
We need to use the Get-TeamUser cmdlet to view the members of the group, but it needs “GroupId” information to use it.
Get-Team -DisplayName "Group Name" | select GroupID
Get-TeamUser -GroupId "419XXX-XXfc-XX6-bXX9-XXXX2ae8a"
Add-TeamUser -GroupId "419XXX-XXfc-XX6-bXX9-XXXX2ae8a" -User email@example.com -Role Owner
Remove-TeamUser -GroupId "419XXX-XXfc-XX6-bXX9-XXXX2ae8a" -User firstname.lastname@example.org -Role Owner
Have a nice day !