The process is the exactly same for older dogs as it is for puppies; prevent accidents from happening by using baby gates and a crate if possible, create a predictable schedule, learn to recognize your dog’s potty signals, accompany your dog outside and immediately reward for all outdoor elimination, properly clean any accidents and supervise your dog until you’re sure that he understands the rules.
Don’t punish your dog if they pee inside. Regardless of all those old training ideas punishment isn’t a good deterrent for house training. Yelling at your dog after the fact just confuses them and makes them nervous around you. If you catch your did in the act you can try to get their attention & move them outdoors. If you’re successful & they continue going once you get outside praise them like crazy.

Punishment is operationally defined as an event that lowers the probability of the behavior that it follows. It is not "punishment" in the common sense of the word,[42] and does not mean physical or psychological harm and most certainly does not mean abuse. Punishment simply involves the presentation of an undesired consequence (positive punishment) when the wrong behavior is performed, such as a snap of the leash, or the removal of a desired consequence (negative punishment) when the wrong behavior is performed, such as the trainer eating the cheese that would have been the reward.[43] A behavior that has previously been developed may cease if reinforcement stops; this is called extinction. A dog that paws its owner for attention will eventually stop if it no longer receives attention.[44]
Animal behaviorists assert that using dominance to modify a behavior can suppress the behavior without addressing the underlying cause of the problem. It can exacerbate the problem and increase the dog's fear, anxiety, and aggression. Dogs that are subjected to repeated threats may react with aggression not because they are trying to be dominant, but because they feel threatened and afraid.[74]
In May 2010, after his dog Daddy died in February and he learned of his wife's intent to divorce him, Millan attempted suicide.[42] In June 2010, Ilusión Millan filed for divorce.[43] In August 2010,[44] he began a relationship with Jahira Dar,[45][46][47] an actress and former stylist and wardrobe consultant.[48] They announced their engagement in April 2016.[48]
Crate training is a vital part of potty training success. As den animals, dogs can appreciate crates as a safe space, and as clean creatures, they’ll often want to keep that sleep space clean. A crate of the proper size is important, as one that is too large may convince the pup they have space to both sleep and eliminate. Puppy pads give dogs the option of relieving themselves in an approved spot indoors. However, these can be tricky to train with if you’re ultimate goal is to get the pup to only potty outside eventually.

Before enrolling with a particular club contact them and ask if you can go to watch a class without your dog. This will help you decide if this is the right environment for you and your dog. Some clubs have waiting lists and you will need to book ahead, some accept people on a roll on roll off basis. Prices will vary from a joining fee and then weekly payments to a one off fee for a certain length of training.