No problem. I found the easiest way to do it is to shoot Values till he starts moving towards the entrance side, when he does, you back out into the previous room. In the hallway a Phalanx will spawn so just back into the outside room till he despawns, then run near the entrance, turn left and shoot valus with a couple of rockets and back out again (before Phalanx respawns). Repeat until Valus starts moving back to the far side. Then make your way over to the bottom of the stairway on the far right side. From there jump and shoot rockets (when Valus isn't shooting his rockets at you). Once you bring him down to 1/4th health, he will start coming towards you. Stay in this area, Valus will try to come towards you and stomp you but his stomp won't hurt you as long as you stay down there. But you can keep sniping him (ice breaker) till he dies. Just make sure the rest of your team don't distract Valus during the last 1/4th stage (having all of them down there with you) helps so he will surely aggro towards you. Hope that helps!