Transferring ownership of a group.
Note: Only GROUP OWNERS can give up their ownership rights for a group. Creators of groups are owners by default, but in certain circumstances it makes sense to transfer ownership to someone else so that this person has the ability to invite other group members. Once ownership is transferred, you give up rights to invite others to this group. There can only be one owner at any given time.
Enter your group
Tap on the SETTINGS icon (gear) next to your group name
Select EDIT on the member screen above the members of your group
Find the member you want to assign ownership to and toggle this member to the OWNER.
Confirm your action in the prompt.