Changing the rear springs/shocks is easy.
The front requires the removal of the struts, of course, which is a bit time consuming. The top bolts are accessed through the engine compartment - on one side you gotta remove the battery, tray, and electric junction box, on the other side the air box has to come out. Then, the sway bar needs to be disconnected, and the upper a-arm removed from the frame (you can leave it attached to the upper ball joint) Once that is done, the struts will come out. Figure a couple hours per side. And use a big ol 24 in breaker bar to get the bolts off of the upper a-arm!
I'm guessing if you're lowering it you may have to shorten the length of the front sway bar connect, maybe the rear as well.