I am redoing the landing area coming out of the front door to the driveway.
Right now there is a step that is almost 9" tall and I wish to make it about
6" or so and slope from there to the beginning of the driveway that is about
6' away.

If it is an open area I can always cut some 1x and use it to create the form
work for the concrete. However, in this case, the area is between two
existing walls. If I cut two pieces of wood and fix it to the ends and do
the concrete, when it's done I cannot remove the wood anymore. Any idea how
I can control the slope of concrete when the edges are two walls?

Thanks in advance,

MC