How to transfer domain name

[missparis]

I sold my first domain on sedo today. It is a .be and I really don't know how to transfer it... I followed the directions yet I always end up with:

Domains with these TLDs do not support changes to the registrant's First Name, Last Name, or Organization: Please use the domain registrant's existing First Name, Last Name and Organization

What does this mean? Thanks

 

[Damion]

Please mention the registrar where the domain is registered