For Icon, you can open where the client is saved and put it in the "costumes" folder. If one isn't there, make one.
For example, if your copy of City of Heroes isn't changed from when the game was live, you can put it in X:/Program Files (x86)\NCSoft\City of Heroes\Costumes. If you used Tequila, open Tequila and find where the client was saved by clicking on Settings and finding the install location in Windows Explorer/File Explorer.
"X:" above would be the drive where you've saved City of Heroes. When in doubt, try C first.