SQL Server 2014 Evaluation downgrade to 2014 Standard

Hello,

we are currently facing a problem and i hope you can help me there.

We installed SQL 2014 Evaluation Edition (including all Features), some weeks later we bought SQL 2014 Standard, this license should be used instead of Evaluation Enterprise because we don´t need any Enterprise features.

But what i didn´t know, my colleague didn´t changed the key and now just 2 days after Go-Live of the system running on this SQL the Evaluation ended and im not able anymore to enter the Standard Key. (seems that this isn´t possible from technical side).

Do you got any idea on this topic?

Thanks,

Michael