The regulation is 61.156. The steps to take are:
1. Complete the ATP Certificate Training Program
2. Pass the new MEL ATP written test
3. Complete a 737 training program
4. Pass an ATP checkride in a 737 sim
The only problem is currently there is only one approved ATP CTP. Embry Riddle. And it is not a stand alone program. To receive the ATP CTP certification from E-R you have to complete their 4 year degree program. Higher Power is working on getting a stand alone program approved but there is no way to guess when the FAA will approve it. Until their program is approved, they won't be able to give you any information.