Issues with adding new acct to site where i had old/different wpmudev acct

Hi,
My name is Ioan Elvis Sersea.
In the past, I registered http://www.englishonlineacademy.com for a wpmudev acct via my former e-mail: maestrosersea@gmail.com
Now, I wish to register the same site, under my new wpmudev acct, with the e-mail: serseaeducation@outlook.com
I'm having trouble getting the dashboard plugin to work and the old wpmudev plugins to update on this site, so it seems I need your help in changing it to my new wpmudev acct.
Thanks,
Elvis
serseaeducation@outlook.com