1. Start Firefox and install addon Cookies Manager+ 1.5.1 at:

Install addon and restart Firefox
B2:  Then go to filehost site you want to login as premium cookies, example with Megaupload
B3:  Login with non premium account
Go to tools again and select addon from bottom


In there you should see cookie named "user" click on it and then click on button "edit"

"Save" Replace cookies premium then press "Save" button
Note: Don't press F5. Please close Browser
How to use download with IDM

   . For others websites use these places to edit cookies

4shared.com---> PHPSESSID

Alldebrid ---> uid

DebridMax ---> PHPSESSID

Depositfiles.com ---> autologin

Easy Share.net ---> PREMIUM

Fast-Debrid ---> PHPSESSID
FileFactory.com ---> ff_membership

Fileserve.com ---> PHPSESSID

Filesonic.com ---> PHPSESSID

Hotfile.com ---> auth

Mega-Debrid ---> PHPSESSID

Megaupload ---> user

Megavideo.com ---> user

Netload ---> cookie_user

Oron.com ---> xfss

Uploaded ---> login

Uploadstation.com ---> PHPSESSID

Rapidshare.com ---> enc

Real-Debrid ---> auth

Turbobit.net ---> kohanasession

Wupload.com ---> PHPSESSID