Yes it's true, you don't need to take the primary off the change the wieghts or rollers. Don't ever wrap the clutch puller or use an impact wrench, because you will damage the crank bearings. Try this once the clutch bolt is removed squrt a few (3,4 or5) pumps of grease gun into the clutch and crank end. The idea is to fill the air space past the threads with the liquid so once you thread in and tighten the puller the hydraulic pressure will pop the clutch off of the crank shaft taper instead of rsorting to metal to metal pressure. With this area full of grease secure the clutch with a spanner wrench install the puller and tighten it up, usually the clutch will pop right off. The first couple of times you will try this it'll usually blow your mind how easily the clutch pops off. If it doesn't come right off remove the puller give it another squirt or two of grease and try again. The grease method is a bit messy but is the only safe way to pull a primary. Be sure to clean the grease out of the inner bore of the clutch and from the end of the crank shaft. Good luck