The guide will be wearing a blue backpack and a white cap with Coconuts Hike Japan logo, waiting for you at the train exit (there is only ticket exit in Hakone Yumoto Station).
From Mishima Station, there are Shinkansen train going back to Odawara (15 min, around 2500 yen) or Tokyo (45 min about 4400 yen) and buses going to Hakone and other places in Izu.