Here are my "after" pics on the hair.
As you can see I've done some extensive cutting and styling to try to approach the "movie look" of Eowyn's hair. It's still not perfect/accurate but it's probably the best I can do given the limitations of my skills and of how they manufactured and curled the hair. It was a lot of work and frankly I wouldn't recommend it for the faint of heart, but if you're patient and go really slow it's doable. It helps that I personally have fine hair with a bit of wave/curl to it and mostly have had medium to long hair styles so I know how my own hair needs to be cut to achieve a certain look.
Eowyn's hairstyle changes quite a bit through the two movies, and I'm only talking about her more simple straight ones, not the elaborate ones like she had at her brother's funeral. The length and amount of curl/wave it has seems to change, which makes sense because a bit of time does pass from her intro in Two Towers through the Pelennor Fields and to Aragorn's coronation. Obviously for this figure I wanted to go for how she looked as Dernhelm, where her hair was largely straight with a loose wave. Actually, her hair is mostly pretty unkempt and messy during those scenes, which is hard to do with this kind of rooted hair.
I used a wide toothed comb and my sharpest scissors, keeping the hair damp and first cutting off all the kinked and tangled ends that come exposed the more you comb it out. Start by cutting the overall length in the back, just a little bit because her hair is almost waist length at its longest so Asmus got that mostly right. The problem is they basically chopped all the layers off the same length which gives it that doll look. What I was aiming for was a long layered look, which helps to thin out the bulk. The best way to do this is to go one rooted section/layer at a time, starting with the lowest, which is the innermost layer. (separate the layers with hemostats or reverse tweezers) Cut the inner/lowest layers shortest, keep the top/outer layers longest, but occasionally some of those layers need to be shortened as well. The key is to rarely cut across the length of the hair, but try to cut
along the length of it (parallel). This keeps it from having that "chopped" look and gives the hair a more chromatic/multilayered effect. Occasionally re-dampen the hair by running a wet comb through it to keep it manageable.
When you get to the bangs and sides you have to go even slower, since these face framing layers are critical. Cut too much and it's over, you can't go back. Eowyn has long bangs that hang down to above her breasts, and I saved them for last. Cut a tiny bit at a time, and remember that the curl in the hair will pull it higher and make it seem shorter. At this point I was targeting individual hairs here and there to thin out the bangs area so it they would have different lengths and not seem chopped. When I was satisfied with the first pass through I combed it all out and reassessed the overall look and did some strategic thinning, mostly in the back. Any stray hairs that were kinked or stuck out in wacky ways were just yanked out.
Finally, I wet the hair down thoroughly and dried the excess, then combed it out. I spritzed hair spray liberally on the comb and combed it through the hair. (I used my own stuff--Aveda Witch Hazel, which is good quality and supposedly all natural) I used this opportunity to isolate and gather individual "locks" of hair like in the bangs area. The wide toothed comb helps this process.
Any handling of the hair pretty much messes it up and simple hand futzing doesn't quite get it back to this look, so you'll have to re-comb with a wet comb to re-activate the hair spray, and maybe even apply more spray. I'm not sure I would recommend wax or grease like some have used on the ACI Aragorn, because Eowyn never had hair that was soaked through with sweat in her scenes, even though she got dirty and messy. I'm hesitant to use gel for the same reason, as it has a tendency to give it a wet look after it dries.
I'm mostly happy with it. The hair now has a layered effect and though I've carefully groomed it, it's still got a flowing messy look to it.
I'll post more pics when I've had a chance to play with the accessories and replaced the helmet strap.