I cant change my ID in digital editions

hi,

I want to use ADE to read ebooks .ACSM.
I downloaded ADE, but when I tried to use it, it shows a very old mail, I changed several years ago, and which no longer exists.
I thus don’t know how to change that ID, and cannot use ADE.
But I definitely need it.
Please tell me how to change my ID, and change that old mail for one I use now

thanks