get an exact measurement from bottom of door to ground and I can diagram how to cut stair stringers. will end up with about 12" treads and approx. 8" risers.
need a good skilsaw, handsaw and pr. of sawhorses.
be sure the ground in front of the door, about 6-10' out and 4' wide is flat and pretty level, if you can put a small sacrete pad there even better.
will take 2 - treated 2x12 for stringers and 5/4 treated deck boards for steps and risers.
stairs are sorta labor intensive but not all that hard to do if you have the method.
I did these for the previous owners kids for a zip line, same way.