Difficulty: Moderately Easy
Step1
The key to making potty training seem really important to a four-year old is to make diapers and training pants seem really uncomfortable. Recruit all the help you can in this area. Praise and reward older children or children his age who come over and use the potty in his presence.
Step2
Don't buy any more diapers. Put the child in thick training pants.
Step3
Don't push the potty. Set him on it first thing in the morning and right after meals. Give him a jellybean just for sitting on the potty not even doing anything into it. Otherwise don't mention the potty.
Let the child have accidents in his training pants. He will not like wet pants. He will naturally start wanting the potty, and the jellybean. After a few accidents you might up the ante, and offer him a bigger treat if he remembers to keep his pants dry. A trip to the toy store, or ice cream store, or a special activity he likes to do.
Step4
If it's the summer, and you have a backyard, take the child out of pants completely when they're playing outside. He will have an accident eventually. If you clean him up and say "whoops, that's okay, we forgot the potty" they begin to get an understanding of where is the right place to pee. Sounds messy, but you can spray off the ground with the hose, and it will make your child aware of his body and that standing and peeing as he would in a diaper is no longer the way to do it.Taking away the diaper as an option allows for the potty to become the new option. Once the child has had accidents on his feet or toys outside, the potty will become an option he won't even question.
Step5
All children mature differently. WIth some kids it only takes a few accidents, some it may take about a dozen wet training pants and a few reward jellybeans before the child will naturally want to keep his pants dry.
Step6
Keep the child in thick training pants until well after he's potty trained, just in case.