Follow the directions in this thread for the VH CGMiner: https://bitcointalksearch.org/topic/gekkoscience-newpac-terminus-r606-bm1387-official-support-thread-5053833
You can also mess with the settings using the current version of CGMIner:
--au3-freqSet AntminerU3 frequency in MHz, range 100-250 (default: 225.0)
--au3-voltSet AntminerU3 voltage in mv, range 725-850, 0 to not set (default: 775)
Also, this thread has a lot of information: https://bitcointalk.org/index.php?topic=827356.1480