Cyclone V GX Hard Power down all Transceivers

I am using Cyclone V GX C9 FPGA with 560 I/Os (F1152 package) in my design, which has 12 transceivers. The FPGA is selected for the number of I/Os required (approx 550 I/Os) and low power consumption as this is a battery operated, handheld device. The transceivers are totally unused and need to be hard power down if possible to minimize power consumption. In Cyclone V Device Handbook, page 3-15, it is mentioned to ground the transceiver power supply of the respective side to enable PMA hard powerdown, but no further information is available. Kindly let me know

1) Whether all the VCCE_GXBL,VCCH_GXBL,VCCL_GXBL power pins need to be connected to ground.
2) How to terminate the unused GXB_RX, GXB_TX and REFCLK pins.
3) Any other details to be considered.