It's true that some slipjoint pocketknives have a harder "pull" than others. Not everyone gets the hang of it right away.
Remember, too, that all folding knives have a natural break-in period and will become friendlier after time and use.
Beyond that, we'd like to tell you that we have a super-secret trick to make it easy, but the best advice we've found on the subject comes from almost a century ago.
(from The Book of Camp-Lore and Woodcraft by Dan Beard, 1920)