Problem with launcher

Hi everyone :) ! I'm trying to play the game ( chinese version ), and, as far as downloading and installing it, everything went fine but when i open the launcher and click "play", i get the same problem this guy had -> [You must be registered and logged in to see this link.]

Now, i read he solved the problem by uninstalling the game and reinstalling it but... I have absolutely no clue on how to uninstall the game :P ! Can anybody help with this, please ?

Delete the game folder OL and Saint Seiya, extrack game again and install.

Thank you :)!