For the psychiatrist, there is no extra training involved. A residency trained psychiatrist should be knowledgeable enough to provide medication recommendations for these patients. The only procedures involved would be long acting injectable medication administration - which can be done by the psychiatrist. However, you would need to keep the medication in office which is another issue itself.
You need to remember that a lot of people with schizophrenia live very different lives from us. They are homeless or in housing. They have no car. Sometimes no cell phones or internet access and would have to go to a library to access internet. They have no job and are usually get monthly checks. This is not to mention if drug use, physical abuse, prostitution, or anything else is also in play.
The other resources everyone is mentioning is mostly Case Management which involves a worker that will drive to the patient's house, check on them, help out with any life things - like getting an ID, setting up a bank account, figuring out bus routes. turning their electricity/water back on, whatever issues come up. They also will pick the patient up and bring them to the appointment and drive them back home. Having nursing available is nice too with injections, drug screens, etc, but most private psychiatry offices do not have enough volume to need nursing. You'd have to pay this person a decent salary which cuts into your income.
Also, to care for these patients adequately, you would likely need an office in the inner city where all these patients live. They would need to be able to access your office by walking or bus routes since most do not drive. This is where most community mental health agencies are. Depending on the area, this could be especially costly or have safety issues with crime in the area. I've had my co-residents who have had their cars broken into while working in these offices during the day.
Now, there are plenty of patients with schizophrenia who are functional enough that they don't need all that. They have secure housing, plenty of money, and family members (spouses or kids) that help them take meds, get to their appointments, stay sober, stay safe, and go to therapy. These patients would be fine to come see you in a solo private office.