The tips on this video come after being shown by several different luthiers. I am by no means an expert but have cut a fair number of soundposts over the past few years. Good luck!!!
Get your tools here:
Inserter Remover Tool: http://fiddlershop.com/soundpostins...
Sound Post Adjuster: http://fiddlershop.com/soundpostadj...
Sound Post sticks: http://fiddlershop.com/soundpoststi...