Using USB Memory Stick to upgrade to 18.10

[Christer Wickman]

Hi Everybody

I would like to ask I have taken home ISO file for KUbuntu 18.10 and put 
it on a USB Memory Stick. Can one use that to upgrade to KUbuntu 18.10 
from KUbuntu 18.04? And how do one do that? Since everything that I have 
read on forums doesn't work. Because when I did as the forum says I get 
a messages that there is no upgrade. I have change on both Server from 
Sweden  to the World and LTS to Normal Releases. But nothing seems to 
upgrade it. I would rather not do a new installtion since that would 
make me lose all data I have on my computer. I even tested the answer I 
got from everybody. But nothing seems to work. Can it a bug that the 
version I have which is KUbuntu 18.04.1 LTS? Hope you can help me with 
these questions-

Yours

Christer Wickman