How hard is it to do yourself? The pull on my Weatherby Vanguard is way too heavy. The trigger is adjustable for pull and creep. I have the manual on how to do it but just need to get a very small wrench to do the job. Is it difficult to get it "just right" or am I better off handing it off to a gunsmith. I like the idea of getting it exactly how I like it by trial and error.