No, practically you can't. Monstercat is extremely weird skin, if you rewrite anything in its code, on next refresh / reload, the original code is rebuilt. There are a lot of included files, which makes extremely hard to work with them.
I recommend not to work with this skin, doesn't worth. Use it as it is, or even better leave it and look for an alternate solution, either here in the Share Your Creations section, either on DeviantArt. You can find a lot of different visualizer skins, many extremely good looking and well working. Recommend eclectic-tech's skins, because slightly - slightly he became an expert of these skins. He wrote a lot of such beautiful visualizer skins.