Changing email address

Hi,
First time I've been on for ages for various reasons but I'v erealised that the email address that is associated with my name no longer exists & have no idea what my password may or may not have been (can't even find it in Chrome's password manager).
I do have a username & P/W associated with that, so I can log in, but obviously would like th eability to receive any updates on posts via email...
So how do I change my email address? I tried simply typing in a new one, but is then asked for my password, so I tried a new one - it didn't like that & I tried the one for my username & it didn't seem to like that, either, so any suggestions would be useful.
Of course, it could just be me & the stinking cold that I have, so I'm off for a Lemsip, Whisky & bed & will try again in the morning, but I thought I might be able to short-cut by asking the folks on here
Cheers
Colin

 

Done (I think ) still suffering from the lurgy!