X3Photo Gallery Forums

Login with a FTP-program to your old provider.
Download all your web-site files to your own computer at home.

Migrate your domain to the new provider (ask them for help).

Login with a FTP-program to your new provider.
Upload all your web-site files to your new provider (in the directory they assign to you.. probably something like 'public_html')

If someone has a imagevue license on a provider and wants to change to another one, how can he request the transfer of the license?

I believe the license is based on domain name not your host. With that said - I'm assuming you have your own domain name...

Yep the license is based on the domain name so everything will continue work without any intervention from your side.

Now I'm using a free provider so the domain has also the provider name at the end..

In that case you will have to re-authorize your new domain name.