If the door has a long bar with one or two springs on it just above the door when it is closed, those are torsion springs.
If it has two springs hanging in the air over the track rails, those are extension springs.
If you have torsion springs, unwinding the old ones and winding the new ones is very dangerous. It is relatively easy if you have done it before and only requires two bars about 18" long of the correct diameter. Not really special tools. If you do not know how to safely unwind them, you could easily break a wrist or take half your face off. Same thing with winding the new ones.
Plus you have to know which one is right and which is left, if there are two of them. The instructions usually will not tell you how tight to wind them.
If you have tension springs, it is pretty easy. Open the door and put a C-clamp on the track on one side to hold the door open. That takes all the preasure off the springs. Unhook the spring cables and take them out of the way. Hold the door up, remove the clamp, let the door slam down. Not on your foot.