This personally isnt that hard but everyone makes a big deal about it ...so here it goes!
To Start go to ::sara
You should spawn on growler IMPORTANT: AVOID SARA BOSS...if it happens to attack you just go in a corner, kill it and move to another corner so it doesnt bother you when it spawns back
To get the Shards your only going to want to attack BREE
thats pretty much it just pray melee so it cant hit you..bree drops shards like crazy.its not even a rare drop
HOPE THIS GUIDE HELPED