I'm going through this for the fourth time at the moment!
My suggestions are:
1. For the last hour before bedtime have a really good play session. Now you have to judge this by your own cocker. For mine it has worn them out but for others is winds them up and are hyped up then so experiment.
2.Then out to toilet. Try and wait for both things to happen unless you know they've recently done a poo.
3. Pop them into their crate saying "bedtime" and put a puppy kong in with them. I use a fill half of it with kibble then some tuna and topped with Primula cheese. Shut the door of the crate.
4. Cover the crate with a throw, leave one end open for air circulation.
5. If they cry for longer than a few mins, start to speak to them in a low calm soft voice. I say "Morgan quiet" at which point he usually stops (not because he knows what it means yet (he's 9 wks) but because he's heard my voice. Then I say "good quiet Morgan, what a good boy" over and over unless he starts crying and then I got back to asking him to be quiet.
I've found that does the trick. On his first night he really did scream but he'd done a poo. I waited for him to be quiet, even if he just drew breath and got him out. Never get them out while they are crying, this will make them cry all the more.
Once Morgan is asleep he'll sleep through the night. But Barney, my English Cocker, didn't. He would wake at 5am every morning. We set our alarm clock for just before that to get him up for toileting before he cried. The theory is that you start to move the time on 15 mins at a time every day and the pup learns to wait for you to come. Barney still created when put back, he screamed until we got up later on even if it was 2 hrs. At that time I had him in a crate away from the other dogs (so that he got used to spending time on his own). By the time he was five months old it was still going on so I moved his crate so it was in the same room as the other dogs and that resolved it, and he slept through from the day I moved him.
Morgan's crate is in with the other dogs but he still cries to begin with, so what works for one doesn't automatically work for another. So if one persons advice doesn't work, try another. What I would say is when trying things out try them for a good few days because alto of pups do better with routine so give them time to get into the swing of it.
Good Luck, hope you start getting some sleep soon.