Can I transfer my V iLoc license to VI on another PC and just return the updated dongle to my HW PC,
Yes. You would just need to have iLok License Manager installed on that other PC, then attach the dongle to it, activate your v6 licence in iLok License Manager, following iLM's wizard's instructions to select your v5 licence to 'surrender', then selecting your dongle as the destination for activating the v6 licence when prompted. The wizard will guide you through the steps when you tell iLok License manager to activate the v6 licence.