There are tons of places selling aftermarket scales and other parts for Benchmades. You should be able to find a YouTube video of how to take apart and re assemble the knife pretty easily! I am considering doing the same to my bugout when I find it.
I feel like Benchmade just designs knives,....at best they grind blades, with THICK edges,..... they might produce a few completed plastic handled "cheapo" models at best, except their more expensive than Custom made "special models". The business seems to rely on people upgrading the handle material, studs ,standoffs,and regrinding the blade geometry, before they get a decent knife.
I have several Benchmade knives. While I've never swapped out scales myself it looks quite straight forward. If you do decide to do it yourself, you will need a Torx head screwdriver. And as Taz mentioned there are a plethora of YouTube videos on how to do so.