A modular suppressor kit includes a modular suppressor and suppressor tool. The modular suppressor includes a barrel attachment portion that has a central passage. The barrel attachment portion is configured to attach to a firearm barrel. The modular suppressor includes a cap portion that has a central passage. The modular suppressor includes a body portion that has an internal baffle structure and an expansion chamber. The body portion is attachable to, and separable from, the barrel attachment portion and the cap portion. The body portion defines a central passage that is alignable with the central passage of the barrel attachment portion and the central passage of the cap portion. The suppressor tool has an engagement feature for engaging with at least one of the barrel attachment portion, cap portion, and body portion.