As mrripguru stated, you will need root access to use this function.
I would also recommend poking into Sw-Soft's forums if you have a particular questions - though some of the posters there are also here, they may be able to give you some specifics on Plesk to Plesk migrations using the PMM.
:-) Hope it helps.
Jennifer McConnell - Director of Client Services
Data393 - Colocation and Dedicated Servers