No worries! I played through Hole in the Oak by using the handy conversion guide to make everyone Underlings, Warriors, Elites, or Bosses as I went as well as making “1d4 gnome” encounters 1 gnome, “1d8 lizard” encounters 2 lizards, etc and it worked out pretty well. I made it through most of the dungeon until 3 gnomes from a random encounter roll killed me just before the dungeons boss.