Another way is to go to 'My Ebay selling' while in seller hub.
Very near the top, over on the RH side, there is a link to opt out and go back to 'classic Ebay'.

"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)