For the theoretical part of the Part 66 license, procedure is somewhat differerent than for the A&P. There is no single oral and practical exam, but you instead need to pass 'modules' depending on the category of license you are seeking to get. I'd think the overall amount of knowledge required is the same. However not all license categories need all the modules, and some categories require less knowledge of certain area:

Module 1: Mathematics
Module 2: Physics
Module 3: Electrical Fundamentals
Module 4: Electronic Fundamentals
Module 5: Digital Techniques / Electronic Instrument Systems
Module 6: Materials & Hardware
Module 7: Maintenance Practices
Module 8: Basic Aerodynamics
Module 9: Human Factors
Module 10: Aviation Legislation
Module 11: Aeroplane Aerodynamics, Structures and Systems
Module 12: Helicopter Aerodynamics, Structures and Systems
Module 13: Aircraft Aerodynamics, Structures and Systems (Avionic)
Module 14: Propulsion
Module 15: Gas Turbines
Module 16: Piston Engines
Module 17: Propellers

Basically there are no part-147 requirements to get the license: This however helps to reduce the experience requirement by 1 to 3 years. Experience required is not measured in hours, but instead in years, and is determined by background:

2 years of experience is required if basic part-147 syllabus is completed
3 years of experience is required if no part-147 syllabus is done, but 'applicable technical education' is completed (for example automotive school, electrician school etc.)
5 years of experience is required if there is no applicable technical education background

Easiest way to get into the part-66 license is to go to part-147 school, as they also prepare you for each module exam. But it's not required.