Change of Registration Information - Is it possible

Hello I've just got a used Leica M8.

The original used is kind to deavtivate his C1 on his computers. He also gave me his user name and password so that I can activate the copy on me computer.

But is it possible for me to transfer the ownership / or link the registration so that I can use my email and password profile for future activation or deavtivation?

Thanks