So firstly, does he have a comforter of any kind? Dummy, snuggle blanket, special toy - anything like that?
Because of if I want to replace parental settling (ie feeding to sleep in your arms) with independant settling then this can only work if he had access to something to give comfort when you're not there.
If there is nothing then he will develop his own comforting ritual - rocking, stroking himself, head side to side, or whatever - it's just any method is going to be more difficult for him without established independant comfort he can access.
If he had a comforter already, then honestly I think the easiest and kindest thing to do in your situation would be to just bite the bullet and tolerate a load of screaming for a few days.
The bottom line is he needs to learn to go to sleep in the cot, without being held. He also needs to seperate milk and sleep (So I'd give the bottle downstairs before going up to bed).
How you do that is up to you. There are 3 main options
â– Controlled Crying. Put in cot with comforter. Say a mantra "sleep time now, nan night" or whatever and leave. Go back after a few minutes. Don't aim to resettle or pick up, just repeat the mantra and leave.
â– Gradual Withdrawal. Put in cot with comforter. Say a mantra "Sleep time now. Lie down quietly. Nan night" or whatever. Lie baby down and get a seat next to the cot. Every time there is a murmur or any movement to get up, lie back down and repeat the mantra. Firm hand on chest. Lots of eye contact, care, compassion through the frustrated crying. But you stay there at all times, being firm, consistantvand calm.
â– Cry it Out. Ensure all needs are met (not ill, right temprature, had access to comforter at all times), put in cot, say nan night, leave and do not go back in.
I favour GW but it will take the longest.
Also look at his daytime sleep and overall routine. Aim for 7pm-8pm bedtime with a nap about 12pm-3pm.