Turn off repeater:
uci set glconfig.repeater.autoconnect='0'
uci commit glconfig
uci set wireless.sta.disabled=‘1’
uci commit
wifi restart
Turn on repeater:
uci set glconfig.repeater.autoconnect='1'
uci commit glconfig
uci set wireless.sta.disabled=‘0’
uci commit
wifi restart
Besides, you can re-assign the switch function via modify the script /etc/init.d/initswitch.