I did it solo by staying at the top. My legendary void MG made short work of the minotaur - only took like 10-12 bullets per minotaur and my MG holds 100/200 (300 total). Additionally, the minotaur gave me special ammo for my void sniper so it worked out well. I duo'd with my brother on our alts, and it was actually harder. The yellow mobs seem to get noticeably stronger with more people. It's actually more or less material grind. The vast majority of my time is spent leveling up weapons and upgrading weapons/armor. Getting legendaries is pretty trivial.