Changing an unmanaged client to managed client

Hi,

We were having initially sepm 12.1.671.4971 which didn't support win 8. We have downloaded and installed unmanaged clients for win 8 build.  Now, we have upgraded to sepm 12.1.4100.4126. How can we change existing unmanged win 8 clients to managed clients ?

Regards,

Anish