If the door is exact same width and height, you can do the install yourself. Roll the old door all the way up, springs will be under no tension. Disconnect them and very slowly lower the old door down. Now just start at the top and unbolt each hinge and roller, 1 panel at a time and remove each one. Install is the reverse, starting with the bottom most panel and working upward. Raise the door, support it with 2 2 x 4 and attach your springs. You do not need to use a Torsion Spring if you do not want to. The old style coil springs will do fine. You may need to get new ones or a spring with more capacity, depending on door weight. The new door may come with them. Recheck your tracks are squared to the door and nothing binds. If you use on, reattach the arm for the Door Opener mechanism. Even for a DIY'er this is only about a 4 hour job.