Replacing icons in a theme

I found some really nice Jaku icons and when I used iExplorer to look for the icon folders all I see in them is a file called icon2x.png. How to I replace an icon with another image within a theme?

 

First of all, thanks for replying in a civil manner. I totally expected a db to respond with "here's how you do it - it's called search."

I have located the folder of the theme and am looking to change icons within that particular theme. I found the folders that you mention but they all have the same named file in them (1 per).

 

So if I checked the icon sets of a theme that wasnt in use they would have actual names not just icon2x.png? Almost like it was showing me a temp file because it was being used?

 

I just replaced about 6 icons under the Jaku theme. All but the photo icons were named icon2x.png. I renamed the old ones to oldicon2x.png. Restarted and no change.

 

Respringing did the trick. Thanks. Can't find the LinkedIn location though. Appreciate the help.