I have used the hammer method for years. I find it best if you can back up the opposite side with a large mass like a 2 pound hammer.

Recently I have discovered another method that I prefer. Put something on the part that will apply a lot of pressure; pitman arm puller, gear puller, etc. When you don't dare to tighten it anymore for fear of breaking the tool, heat the part surrounding the tapered stud with a propane torch. I find that 10 to 15 seconds is usually enough and it will come apart with a lot of force, so keep the nut on the end of the threaded part.