STEP 1: attach mount legs into the crossbar, and fasten the self tapping screws through the crossbar and into the leg.
STEP 2: Loosen the bolts as the picture shown, and reserve more space for the bottom test.
STEP 3: Swing the mount legs strap under the gutter, and make sure that the strap is fully located under the gutter.
STEP 4: Adjust the position of two side mount legs to choose the suitable place.
STEP 5: Fasten the security bolts by phillips head screw driver.
STEP 6: Finish the installation.