Guild Wars 2

I was wondering if i can change my server for free if i delete all my characters from the other server?

yes you can

Accounts without active characters

The transfer fee is waived for accounts without any active characters. This allows players just starting out to change to another world that is not full. You also can transfer without cost if you delete all your existing characters. The next time you log on without any characters, you will be prompted to choose a new home world.

Thank you, this is huge news for me, because all my friends play in EU server and i play in America.

Remember if server full you are out of luck. Also put all thing in bank you want to keep.