I have done it a couple times and thought it was fairly easy. Remove the valve covers and rocker assembly. I used a $7 Sears heavy duty telescoping magnetic pick up tool and basic mechanical fingers. Using the combination of the two worked good to pull the lifter out of the bore up and then slide it sideways until it would fit out one of the passages. In most cases I could just use the magnet to pull them up and out and other times I would have to try to get the fingers to grab at the retainer clip on the top of the lifter. Between the two of them it works pretty good. No need to take the intake off unless you really want to. Having the intake and valley pan would give you a good look at the cam shaft if needed. But if it is just a noisy lifter, just replace them all at the same time with the method above. Don't forget to soak them in oil/lube before install.