How to beat the eidolon giants?

So I got a bit better at the game, got my first two primes and a couple decent mods, but that matters little when my amp does minuscule damage against that big guy, leading to me getting overwhelmed by his little friends. I know eidolon lures kinda help with the small ones, but they take three out of… many more. Would crafting the first craftable amp boost my chances? Also, what’s a good way of destroying his body parts after you’ve stripped the void shield? I’ve heard the Rubico with radioactive bullets and multishot is supposed to be good for that, but is it true? Obviously I understand that soloing what’s basically a raid boss isn’t on the table, but I’d like to at least see some fruits.