How do people get dilaudid and oxycotin and numorphan (oxymorphone) so easily when they are celebs?

Like Everything Else. They buy it illegally or they get a doctor to write them a prescription. Some perfomers actually do have legitimate pain problems but the lifestyle sometimes leads to other complications and addictions. When you have $$$ $, you can always find those willing to oblige with whatever.
Money talks. As dr. Marx said, if you have the cash you can get what you want.