I would need a more detailed instructions mate...Cheers though
You can modify the fan speed by accessing the miner through SSH(Putty).
You can check this sample guide from here https://bitcointalksearch.org/topic/how-to-overclock-your-s9t9t9r4-to-18ths-free-4425212
As he said only edit the line "bitmain-fan-ctrl": true," and "bitmain-fan-pwm": "95",
or you can modify the fan speed from the dashboard you can check this guide https://bitcointalksearch.org/topic/solution-for-antminer-s9-fans-speed-up-down-every-20-seconds-2690140