Its pretty easy...the model you have is easier than the Astrale 8 which has two separate sensors...both your cadence and wheel speed sensors are integrated into one dual channel RF pod. Mount the computer on the bars and then the sensors on the bottom chainstay and you are good. Just adjust the position of each sensor within 5mm for good pick up. A hint is to cinch down the tie wraps with flat nose pliers and then snip them off to get a good secure fitment of the sensor base to the frame and magnet to the crank arm.
A piece of cake really. If you struggle, your bike shop can hook you up for a nominal fee.
HTH,
George