Converting a Citrix XenServer VM to a Hyper-V VM is supported, and it is done using the P2V process. The procedure described in this recipe is exactly the same as the one used for converting physical servers to Hyper-V VMs.
You are not required to remove Citrix Tools from the source VM to start the P2V conversion.
However, note that only running VMs are supported for the conversion in VMM 2012. The source VM must also be running a supported Windows guest OS. You can check the supported operating systems at http://technet.microsoft.com/en-us/library/hh427293.aspx.
Additionally, the source machine needs to meet the following requirements: