In order to ride this trail you will need to stop by the guard shack on Laukahi Street and pick up a temporary day pass. This will allow you to park in either parking spot dedicated to users of Wiliwilinui trail.
Once through the trail gate you follow the paved road for awhile until you see the trail signs for Wiliwilinui. At this point it becomes jeep road the rest of the way. The jeep road is wide enough to ride side by side with another rider. The trail doesn't have much foot traffic but do watch for hikers and even the occasional utility truck.
Bring water. There is shade but you will be out in the sun for much of the time. The whole trail isn't a climb. There are several level spots as well as a couple of short downhill sections.
After about 1.6 miles the trail continues but only as a hiking trail. There is a park bench here and a bike rack to lock your bike too if you decide to continue on foot.
Clicking on the link above you bring you to Google Maps where directions to the trail are plotted in from Honolulu Airport.
Download the GPX file and use your favorite software to upload trail data to your GPS. Right click on the link and select "Save Link As..." in order to download it.