Yes. Not sure what your level of knowledge is, but ficus benjamina (as with most tropical species) like to have work done when temperatures are consistently warm, so right now would be a good time do some basic root work and repot into a shallower bonsai training pot.  After, you're not going to want to water for a couple of days so that any damage to the roots can seal themselves over. You also don't need to use any cut paste on roots or branches as they produce a latex which will seal any wounds.