LED bulb replacement in Dusk-Dawn Outdoor 175W light
You will need to bypass the ballast! Failing to do so will fry the LED.  

Corncob LEDs are always a bad idea. They are inefficient. They intentionally defeat the best characteristic of LED -- that they make a wedge of light, which is what you really want.

Look around at lights. You have wallpack lights painting a super bright spot on the wall (useless), path lights lighting a huge circle not just the path ... and oh, the skyglow!   Just here at this restaurant the car dealer's halide light is blasting in the window from across the highway. Meanwhile at the gas station,  the canopy lights make the pump area glow pleasantly, but even the trees in front of the place are pitch black. Their lights are LED and are properly aimed. This saves them a fortune.

Cost savings is in aiming, not LED

Fact is, halide lights are about as efficient as LED. If you go with a corncob LED, you won't save any money unless the LED is less bright: this is a common con-job when selling LEDs. I saw one ad claiming their 45 watt, 3300 lumen LED is more efficient that the 175 watt metal halide . um... a 175W MH is 14,600 lumens. It would take 4 of those corncobs to make the same light, and it's actually less efficient.

Your linked one is 7000 lm, half the brightness of your MH.

On the other hand, if you aim the LED in exactly the wedge of light that you want,  you're still no more lumen efficient, but you're only paying for the lumens that are actually on target.   We once had seven 400W halide lights (3150W) lighting up a 400' right-of-way (and also, half the town). They were on city poles, so the location was not good. This was costing $1600/year.  I specced a mere 250W of extremely well-aimed LED spots, $125/year. 

Anyway, for former halide lights, I just mount an aimed  fixture inside the old diffuser, aimed out the hole in the bottom.  A tiny amount of splash light makes the diffuser glow, it looks nice.