Since KoG Lethal has split into KoG Echo, I need you to click "Community" at the top of the page, then click "Join A Clan" in the drop down menu, scroll to the very bottom of the page until you see "You are a member of the following groups". Click the bubble next to "KoG Lethal" and then click the button that says "leave group"
Go back to the "Join A Clan" page, find "KoG Echo", it should list "KoG FaceUp XS & KoG Romulus" as Group Leaders, click the bubble next to "KoG Echo", scroll down to the bottom of the page and click the "Join Group" button, fill out the appropriate information, then send/submit the request.
Go back to the "Join A Clan" page, find "KoG Echo", it should list "KoG FaceUp XS & KoG Romulus" as Group Leaders, click the bubble next to "KoG Echo", scroll down to the bottom of the page and click the "Join Group" button, fill out the appropriate information, then send/submit the request.