
I refinished mine last Spring.
I suggest removing the bottom step, covering the starter battery, and taking it home to experiment prior to tackling the entire ladder. If there only minor scratches & scuffing, you may be able to lightly sand and apply a few coats of sealer. Mine were moderately worn and had several dings; therefore, I stripped all of the old finish down to the wood veneer.
I used a citrus based chemical peeler and hand scraper to remove most of the old finish. Beware that Beneteau used a pigmented varnish that has an opaque appearance, you have to remove that final layer to get to the bare wood layer.
I used a random orbital sander with 150 to 220 grit discs to initially prep the surfaces. Go slow and be careful not to penetrate through the veneer. Be sure to apply about three layers of masking tape against the intersection of the step and white vertical surface of the engine cowling to prevent the edge of the sanding pad from scuffing the white surface. After vacuuming and using a tack cloth, I wiped the surfaces with denatured alcohol. Mask all of the surrounding areas with paper and tape. I applied two coats of Min Wax Wood conditioner and then applied two coats of Min Wax stain mixed with 2/3 Sedona Red and 1/3 English Chestnut and allowed it to stand for about ten minutes before wiping between coats. After a very light sanding, I then brushed on two coats of Min Wax Helmsman spar urethane with light sanding between coats; however, I was not pleased with the result. I then sprayed about 3 to 4 coats of Helmsman semi gloss ( spray can) with minimal sanding between coats to achieve a better result. Finally, I lightly hand sanded with 400 and 600 grit paper and steel wool, then used aqua buff compound to bring out a nice luster. I applied Sea Fit 1" non skid tape from West Marine using a socket as a template to cut the bull nose on the ends of the tape. The new tape is much superior to the tape that Beneteau used in preventing me from busting my butt repeatedly when the steps are wet; I haven't had another incident to date!
Note that Beneteau recommends using Mo Hawk pre catalized lacquer finish; however, when I tried it on the bottom step at home, I wasn't satisfied with the result. In addition to the urethane finish looking better, I believe it will be more durable to foot traffic and will hold up better as the steps get wet quite often. This is a two to three weekend project to prep and allow adequate drying time for the multiple stain and sealer coats. All of the materials were purchased at a big box home center. My understanding is that Lowes custom mixed Cabot stains; however, the Lowes in my locale didn't offer that service.
As Gunni mentioned, if you are sailing offshore, the step surfaces would be safer with a better non skid surface like treadmaster. I haven't had any problems since refinishing; however, I have enough tape remaining that I could apply another row on each step if needed. My old Hunter had a ladder with rubber surfaces with raised circular areas that were more durable and safer.