Runescape account recovery?

So basically I want to remove the email and recovery questions from one of my runescape accounts so I can sell it. Problem is, I can't remember the email that is registered on it..

When I go to account recovery, It gives me the 6 tries to put my registered email and then tells me I have to wait an hour to try again because I get them wrong.

I'm trying to recover the account so I can remove the recovery questions, but this email thing is getting in the way. What do I do?

Thanks

Edit: another thing to add, I can't even change the password because I don't remember the email I used on it..

 

You could try out this guide. If that doesn't work I don't know of any other way to recover it and change the questions