Add sub-section about changing group owner

doc/user/group/index.md

@@ -163,6 +163,24 @@ If you change your mind before your request is approved, just click the
 
 ![Withdraw access request button](img/withdraw_access_request_button.png)
 
+## Changing the owner of a group
+
+Ownership of a group means at least one of its members has
+[Owner permission](../permissions.md#group-members-permissions). Groups must have at
+least one owner.
+
+Changing the owner of a group with only one owner is possible. To change the sole owner
+of a group:
+
+- As an administrator:
+  1. Go to the group's **{users}** **Members** tab.
+  1. Give a different member **Owner** permissions.
+  1. Refresh the page. You can now remove **Owner** permissions from the original owner.
+- As the current group's owner:
+  1. Go to the group's **{users}** **Members** tab.
+  1. Give a different member **Owner** permissions.
+  1. Have the new owner sign in and remove **Owner** permissions from you.
+
 ## Add projects to a group
 
 There are two different ways to add a new project to a group: