Need advice on expressing my male cat's bladder

My little boy recently developed a neurological issue affecting his hind left leg, causing a limp and preventing him from urinating on his own. I took him to the emergency vet, and they cleared his bladder. He wasn’t blocked, and when his bladder is expressed, he can urinate. Instead of opting for euthanasia, I decided to help him and see if he recovers. If not, I’m prepared to care for him for the rest of his life. Any advice or strategies for taking care of him?

What did the vet say you should do to clear his bladder?