Can't remove ownership of subgroup or leave the group

I have two accounts which I'd like to merge into one, both of my accounts are owners of all groups and subgroups.

Account1 I want to delete Account2 I want to keep

I can leave the parent group with Account1, but when I do that I still see all the projects because I'm still owner of the subgroups. If I go in member settings foreach group I can't leave nor can I remove my rights from either account for Account1.

Meaning I can't delete my Account1 so I can't add my email address on Account2 because I can't change my primary email on Account1.

So how could I manage to get rid of my Account1 but still have Account2 with ownership of all projects and the email address attached to Account2 which is now primary of Account1?