What shall I do if I want 8-bit I&Q data transmitted by USRP2

Hi,
I want a complex sampling rate higher than 30Msps, and the 16-bit data
transmitted by USRP2 is too much for me. So I wonder if the 16-bit data
can be changed to 8-bit before sent to the Gigabit Ethernet interface.
What shall I do?