Don't pay the dealer to doit, this takes about five minutes and is very basic.
First prop the hatch up, the closer to full open the better.
Second, locate the spring retaining clip at each end of the strut.
Third, with a small point, flat blade screw driver, carefully pry the spring retaining clip loose from the strut end. It actually kinda slides in a groove until it's free of the strut end. Repeat for the other end of the strut.
Forth remove the strut from the vehicle.
Now you can install the replacement strut. Installation is reverse of removal; you should start with the retaining clips pulled back from the strut ends. attach one end, secure the retaining clip, then adjust the length of the strut and the height of the door until you can attatch the other end. I found that securing the bottom end of the strut to the body first made it easier to attach the top, instead of the other way around.
Also, a good place to look for parts is www.hondapartsdirect.com
; best prices on new dealer, OEM parts as I have found anywhere.