Can't change my email? (login name)

[KyouOu]

So the emai is the "login name" too...

 

i want to change some gmail cause what my current email i get slowly the mail..

but in settings i cant change it...(only pass)

I have dinamical ip (not cause restart rooter like hell) and this everyday get 1 mail copy pw shit annoing esp when u need to wait 5-10 min to get the mail

 

There is a way to change it?