Before you add an admin, make sure you understand what an admin can and cannot do in a colony.
Add an Admin
Navigate to the your colony's Settings.
Click the Organization tab.
Paste in the the new admin's Ethereum address and click Add Admin.
Yay! Your just added an admin! 🎉
Remove an Admin
When you hover over an admin card in the Organization tab, a Remove button will appear. Click it to remove the user's admin privileges.