I have three exterior walls that need all the studs and the top plate replaced. I am a novice carpenter and I try to learn everything through research and study first. The walls would need realigned as well as raised due to prior cuts on the bottom of the studs to replace base plate. The two outer walls need the bottom brought in and the front wall dividing the home from the enclosed porch needs the top brought in. How do I replace and fix all of this without doing any harm to the siding or it falling or coming off?
I really think you have a situation that is going to be a bit more than a novice carpenter should tackle. The normal procedure to replace wall framing involves placing a pretty hefty beam under the ceiling joists and jacking the entire section of joists at once so the weight is off the stud walls. The studs and plates can then be removed. Other considerations will be electrical, windows etc. It is going to be impossible to properly replace the entire wall frame without also removing the exterior sheathing and siding.
What you are faced with is a MAJOR repair. You will need all the right tools, calculate the proper wall height, plumb the walls, interlock the corner plates together, support the roof load, and try to do this fairly quickly as the house is going to be wide open for a while during this process.
This is a good example of when you should hire a pro and see if he/she will allow you to assist. You will learn a lot and have the security of knowing the roof isn't going to fall down on you during the process. Consider the costs as tuition in you carpentry education.