Upgrade from Sql Server Entreprise to Evaluation edition, it is possible?

I'm having some trouble upgrading from an Entreprise edition of Sql Server 2008 R2 SP2 to an Evaluation of Sql Server 2014 SP1, and I begin to wonder if it is possible? I didn't found anything about it in the supported version and edition upgrade guide : http://ift.tt/2aAzUlg

It says that you can't migrate from SQL Server 2014 Entreprise to Evaluation, but it says nothing about previous editions.

Thanks.