That's the first thing you'll need to do--create an account for the new e-mail address. Then, you can use the "Replace Admin" feature to replace the account on your hub using your old e-mail address with the one for your new e-mail address. See here:
I can't remember quite how changing things on the Community works other than that I use my Hubitat account for login (not sure if the social options still work, but I wouldn't recommend them anyway...) and think I was able to add it as an additional/alternate e-mail account, make it the "primary" (both after verifying), then remove my old one. This may differ depending on how you registered your account initially.
