I was given a NIB ARF Ultra Stick and there was a lot of wing damage, this wing tip was so bad I just used my heat gun to soften the glue stick crap they used and removed the old tip and made a complete new one. Ribs were also broken on both wing halves so to get in and do all the repairs I removed all the covering from the bottoms then recovered. With these Horizon pieces of junk at least they used Ultrakote so getting the correct matching covering is easy. I just warm up the covering at the tip with my iron and stretch it over the tip and iron it down tight at the edges. I leave all the waste covering then turn up the iron a tad and run the iron over the top of the covering to shrink it tight then trim the waste and iron it down to the edge.
Nothing secret or needing any tricks. Ultra shrinks and holds very well so it is easy. The Chinakote from Hobby King is every bit as good if not better then Ultra and at 13 bucks for a 5 meter roll you can't beat the price.
After I ran my iron over all the open bays and sheeting to remove the sag and wrinkles I also went over the top of the wing and removed all the wrinkles and bubbles that were from the factory. The wing now looks better then new and no longer has all the broken ribs.
The covering isn't touching any of the supports inside the tips, it just lays tight from the last rib and the edge of the tip then gets tightened.