Start at the Roaring Brook Trailhead. This trailhead is opposite the road entrance to the Ausable Club on the west side of the road. In fact, you may just want to drive ¼ mile to the golf course where you will have a great view of the slides on Giant. Once you start hiking east on the Roaring Brook trail, Roaring Brook will be on your right. You eventually pass two short trails, one leading to the base of Roaring Brook Falls and the other to the top of these falls. Eventually, Roaring Brook Trail crosses Roaring Brook. This is one possible entry point where you follow the brook upstream instead of following the trail. However, the trail and the stream stay reasonably close together for another ¼ to ½ a mile and you are already going to be doing a lot of off-trail hiking, so it may be easier to follow the Roaring Brook trail and then cut over to the stream after ¼ to ½ a mile.
Once you begin following Roaring Brook upstream, you can either rock hop in the stream, follow barely noticeable herd paths along the stream, or a combination thereof. When different tributaries branch away, always follow the main stream with the most water. After close to two hours of following the stream, you will come to two distinguished landmarks that let you know you are getting close to the rock slides. First, you will pass a huge, house-sized boulder on the left. Second, you will reach a mini-slide, about 100-feet of bedrock. It is very slick at the top of this 100-foot pitch. After this you basically follow the main drainage, which opens into a talus slope. Several hundred feet up, it is more bedrock. Also, at this point you can see upwards to the second feather of the Eagle slide. Take note of it because if you traverse to the right or to the left of it, you need to come back to it because it is the easiest exit out of the slide at the top. This is probably where you will want to change into your rock climbing shoes if you brought them. Take note, do your best to keep your climbing shoes dry—avoid the wet sections of the slide whenever possible. The climbing now gets very steep and very exposed (Class IV). You definitely do not want to fall here. However, you can follow cracks and flakes between ledges every 30-40 feet. This is a great climb; for me it was an “I can’t believe I did this!” type of climb. After several hundred feet of wide open slide climbing, you reach the 2nd feather, which is only 20-30 feet wide. It is still very exposed, but less steep compared with the wide open slide areas. At the top of the 2nd feather, change back into your hiking boots. From here is it a short hop, skip, and a jump on a herd path through cripplebrush to the Roaring Brook Trail, the summit being several hundred feet to the left.
I myself would not attempt this climb without rock climbing shoes.
Take the Roaring Brook Trail back down to your car. Note that on your way down, it junctions to the right, while the Ridge Trail veers to the left.