No warning?!
You've had warning after warning after warning. Times 8.
He's repeatedly shown you what he is. A middle aged strop monkey flounce bunny.
And you're inflicting this on your poor kid again and again and again.
Of COURSE you know what to do.
Change your locks.
Remove his details from any bills.
Inform Council Tax office he no longer lives there.
Pack all his stuff neatly in a box.
Check if you're still blocked. If not, send a clear polite businesslike message saying the box will be on your doorstep on this date at that time and if he doesn't collect it, will go to the tip.
If blocked, do you have contact with any of his friends/family? If yes, send them that message to pass on.
If no contact details, keep the box for a reasonable time - then dispose of it.
Keep records of all attempts to contact him.
Grow your self respect. Step away from the 'any man is better than being single' mindset. Focus on you and your child.
All the best.