1. Purchase a comfortably-fitting harness and lightweight leash with a secure clip. Do not use a collar, as the cat may be able to slip out of it. You want the leash to pull from the chest rather than the throat. The Walking Jacket (available at metopet.com) is a fine alternative to a harness, virtually escape free, and with the leash attached mid-back, for comfort.
  2. Put the harness and leash somewhere near kitty’s sleeping area and leave it there for several days to accustom him to its appearance and smell.
  3. Wait until just before his normal mealtime, then put the harness on the cat. You should be able to comfortably slip two fingers between the harness and his skin. 
  4. Immediately feed him his favorite meal and praise him when he is finished.
  5. Let him wear the harness for awhile. If it seems to bother him, distract him by playing with a favorite toy.
  6. When your cats seems to be accustomed to the harness, take it off.
  7. Repeat steps 3 through 6 for several days, leaving the harness on longer each time. 
  8. Next, attach the leash to the harness and let your cat walk around the house, dragging the leash. Watch him carefully that he doesn’t get tangled up around furniture. 
  9. Praise him for being such a good cat, and give him some loving hugs!
  10. Repeat steps 8 and 9 for a few days, until the cat seems to accept the harness and leash.
  11. Next, let him walk around as usual, but pick up the leash and follow him in his wanderings. Keep the tension slack, so as not to restrict his movement.
  12. Practice step 11 for a few days.
  13. Teach kitty to follow you by talking to him in a cajoling manner and lightly pulling on the lead. Don’t fight him. Leash-training should be a pleasurable experience. If he tugs at the leash, simply stop until he relaxes, then move on.
  14. Now you’re ready to move outdoors. Do it gradually, and take your first short excursions in your own back yard, or in a quiet area.
  15. Gradually increase his exposure to the sights, sounds and smells of the outdoors.
  16. The most important thing is safety of course so be very patient with this process. Do not attempt an outdoor excursion until your cat is TOTALLY cool with the indoor leash walking. And, not all cats will accept leash training but if you follow these steps, you will likely be successful and . soon, the two of you will be Walkin’ Out The Door!