I added wrong owner to my club How do I remove her

[Sarah36 Islay]

I wanted to add my partner as 2nd Owner but I completely messed things up by adding wrong name by error, THis other owner who I added hardly logs into SL and I don't even know her from my group. Feeling worried what she may do now she has the same powers as me. I find it impossible to remove her title owner.

[Rolig Loon]

It is impossible to remove an owner from a group.  She'll have to remove herself, if she wants to.  This is why there's a popup warning when you are about to assign someone to the Owner role, advising you that it's irreversible.  The only safe person to add as a co-owner is your own alt, since that's the only person you can trust to do exactly what you want with the group.

If you are really worried, the best thing to do is to eject everyone else from the group, and then leave yourself.  When the co-owner is the only person in the group, it will vanish within 48 hours.  Just be sure to sell any group assets to yourself or to a new group before you do that.