1. Make sure you turn the machine off, unplug it, hit the power buttons a couple times and then wait 15 minutes before working on the machine. This is a little overboard but it ensures you won't do any electrical damage when taking the head out.
2. After taking the head out, clean the area where it was thoroughly. Ink builds up and prevents the head from moving during alignments.
3. When taking the dampers off, lift straight up so as not to break the manifold. When putting the new one on, wet the manifold with cleaning solution so the damper slides on nice and smooth.
4. Check your head cables before installing them on the new head. If they are damaged or dirty, you should replace them.
5. You should take the alignment spring out before the head. This way it doesn't pop out and disappear. Also be very careful taking it out. The tend to go flying and they are hard to find afterwards.
6. Do the alignments in the order the appear in the alignment menu. It should be, Bias, Vertical, Horizontal, Bi-Directional Default and then User Menu bi-directional in that order.
7. The manual will tell you to push and hold the left, down and right arrows to enter service mode but that is not the case anymore. Instead do this: With the back power switch on and the front power switch off, push these buttons in order > down, right, left, up, right, down, left and then press and hold left, down and right at the same time while power on the front switch. You have about 5 seconds to do all that so it may take a couple tries.
I don't use the head rank usually. I never flush the machine before the install. Just have some paper towel ready for the ink that will come out when you take the dampers off. I never flush the head before install either as it causes more problems than it prevents.