lost info

hello dear stienberg team.

i own cubase 7 (installed for some yers) i lost my e-mail that i reg my product at my steinberg.
i have the box and proff of buying. i contact my dist and he cant locate the mail.

i want to delete my accout and give my partner (we split) the cubase so he will reg on his name and update when he want to.

please help needed