From Flagstaff go north on US 89 for about 14 miles. Turn left on the dirt road directly across from the Sunset Crater Rd. You will see signs telling you, "Sunset Crater next right." Follow the road back and pay attention to the signs. Follow the signs that lead you into Locket Meadow. Once in Locket Meadow drive to the far end of it until you see a Parking area for day use only. The parking is on the left hand side, and the trailhead is on the right hand side of the road. The trail is more of a road, which lets Forest Service vehicles through. The trail is open to bicycles and horses. The trail is 3 miles, which makes this access to Fremont the shortest route.
Once in the Inner Basin Study the mountain. There are a variety of routes you can take. There are different ridges you can take to the summit. From the pump house in the Inner Basin follow the trail back into the Inner Basin even further. The trail leads toward Fremont. Once you get fairly close leave the trail and hike straight towards Fremont. You'll end up hiking straight up a steep rocky slope until you reach the Wheatherford trail. If you hike north to the saddle between Doyle and Fremont you can take the northern ridge. This ridge rises 1,200 feet and is a tedious climb. You just want to stay on the left side of the ridge. You can also climb Doyle from this Saddle. It is recommended to hike Doyle and Fremont in the same day.
If you hike south on the Weatherford trail you can take other routes to the summit. You just want to make sure you got a good look at the mountain from the Inner Basin. There are some steep minor ridges on the west side that are climbable.
Walking Sticks are nice to have coming down the rocky slope under the Weatherford trail. The slope has loose rocks that can cause you to slip.