The key for me was using the pile bunker. The charge attack chunks the spider. And then I went with reverse joint legs. You want to stay right under it as much as possible in the first phase and those legs help greatly with that. Fit high stagger shoulder weapons and whatever you want for the other arm. Then in the second phase the legs allow you to stay in the air much longer and you want to focus on stying above it. Just keep pounding it with that pile bunker. Took me 2 or 3 tries after I figured out that setup