Ok, do you know how to find that password in your browser?
But one thing to remember. Change your email address in your profile first. And when you do change your email address, this site might(I do not know) request that you verify your new email address.
Some sites request email verify to change password. So if it still has old address, you can not verify.
Do you understand? And what browser are you using?
Different sites use different methods for changing profile details. There is not one common way.