How to remove a super admin?

[محروم.كوم]

I had my forum setup for me by a developer. I just looked at the Admin CP and checked Administrators and he is still set up as a Super Admin* when I tried to change his setting I couldn't. For the sake of security I would like to be able to remove all Super Admins except myself (the site owner). Is there a basic step by step instruction on how to do this? I'm new to all of this so if anyone could help explain it in easy terms I would appreciate it.

Regards*
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