1. Make lots of money.
2. Buy a farm.
3a. Build a dairy barn
3b. Be lucky enough to have a dairy barn just sitting around.
IF 3b, improve said barn.
4. Buy stainless steel milk tanks and state-of-the-art milking equipment.
5. Buy heifers, preferably lovely, placid Holsteins and Gurnseys that give milk rich with cream.
6. Do all the dirty work. (This is where, tragically, many wannabe ice cream makers fail -- where the shit hits the fan.)
7. Get up before dawn and milk the heifers. (You'll need to do this again in the afternoon; don't go home and take a nap.)
8. Put the milk in a tanker truck and haul it to the creamery every day.
Alas, you won't have time to taste the sweet part of your labor, because you'll be up before dawn to milk those girls again. ;)