How to flash ac58u firmware?

i already build ac58u for LEDE, it make *.itb and *.bin file. how to flash it.

See the git commit that added support for this device:
https://git.openwrt.org/?p=openwrt/openwrt.git;a=commit;h=87c42101cfb001b4bd418d1201fa4d8c822dc77b