The how is pretty tough. I have been acumulating buggy parts for a while now. The first thing to figure out is 1,2,3, or 4 seater. Then you have to chose rocks or mud. Mud rigs tend to be rigid suspension high horsepower. rock rigs flexy and high torque. You could use a rock rig for mud occasionally but you have to chose which you want to do and take the compromise on the other.
While making these choices you need to do a lot of research. Not so much into details but look at a lot of rigs. What do you like what do you hate. When building from the ground up you want to make sure that everything has a place and looking at already built rigs will help with seeing what is an afterthought. Buying a chassis is a great/cheap way to start. For the price of tube, time spent bending, welding, designing you come out way ahead of the curve.
Clearly we can't walk you through everything that you can do while building but the place to start is research. While you research ask the logical questions. Is this something I can do? How much time can I spend on this? What about money? What am I going to sacrifice to do this?
I am taking a different approach with my buggy. I am going ultra light, lower horsepower, small tires. My thought is a 2 seater that is light enough to toss around. Light enough to tow with an F150, but still built to meet comp specs just in case. If I had to guess, I would say I have about 60 hours in design, 40 in parts hunting, and another 20 just agonizing over misc crap. I haven't even started to build yet.
