Usually it should require a puller. You can try checking for damage or burrs on the mating surfaces and then do a little work with emery or grinding paste to make it a good taper fitting. It is the taper that holds to loads, not the woodruff key on these kinds of connections. The key is usually just for alignment.
The Woodruff key is there for catastrophic failure . It shears off before things lock up bad and you go down .
That is inaccurate.
Who said the key was to hold any torque force ? The tapered crank to tapered sprocket takes it all .
