UNPLUG THE TOOL FIRST!:thumbs_up
Look at the new blades and you will see that not all the bolts need to be removed because the knives have slots there. The plastic jigs do work, but don't force them. Blow the area out good both before and after you take the dust cover off. There is a metal lever on the right that locks the head in easy position while changing the knives. Rotate the head until it locks in place. change that blade, push the lever down and rotate to the 2nd knife and change it. Make sure the dust cover depresses the lever when it is put back in place to unlock the head.