Approach the faculty in the graduate department of the subject in which you want to start a doctoral program. Graduate faculty usually also teach doctoral students. You will need a full set of faculty members in your doctoral department.
Have the faculty discuss among themselves and decide the program's objectives and direction. What do the faculty hope that their doctoral students will achieve? What kind of academic programs will they take part in? Will they have opportunities to collaborate on academic papers?
Determine the structure of the program. Most doctoral programs have some mix of actual coursework and dissertation work.
Determine what will be the obligations on doctoral students? How will they balance their own coursework with teaching and working on their dissertations?
Design the specifications for a student's dissertation proposal and dissertation. Will there be length requirements? What kind of research will you require and how much? These specifications will probably be specific to your subject.
Draw up and publish a student handbook outlining the program, its specifications, its requirements of, and opportunities for, students.
Hire administrative staff. You will need people to keep logs of each student's coursework, grades, dissertation proposal and progress.
Recruit people to do recruitment efforts. These efforts can be among your school's current graduate students or they can be targeted to students at other schools.
Have the faculty decide what the program's admission requirements will be and who will be on the admissions committee. Often, graduate and doctoral program admissions are decided by faculty.
Secure funding for your program. If your faculty are pulling double duty with graduate and PhD students, they will need higher salaries. Also, PhD students are almost always funded by the university.