If you are a doctor you will be in luck. What you have done is crushed the Nomex honeycomb internal sandwich.
The best way to secure the dent is to inject epoxy into the indent. I drill small holes along the indent about 100mm apart but only through the top outer layer, not the whole way through, quite a delicate job with a power tool (looks like I might be loosing you here!) anyway once you have a row of holes you get your syringe and needle and whilst dry just push the needle into the sandwich trying to join up the holes, the internal holes should join up in the middle between the external holes, making a channel along the damage. Then get a very viscous (runny) epoxy resin and inject epoxy into the channel that you created, once it is full of resin mask the holes up to stop it running out and hey presto you are half way there.
What this has done is made it waterproof and no longer soft, a common mistake is to just fill over the top of the crushed Nomex, this still has the soft damage underneath and the patch usually fails soon after.
The finishing is where it gets some what within your ability or lack of it. Basically fill the damage externally to make smooth and then gelcoat over to make it disappear. The disappearing part tends to be the hard part! To get the gelcoat to match and to sand smooth and polish sounds easy but never is.
So there is your few simple steps as you asked for, the skill to do it is in the other book not mentioned here.
Happy repairing!
