You don't add dice for Reinforcement tokes as you add them after rolling the dice for your units.
Rules Reference page 11 wrote:
Reinforcement tokens do not contribute dice to a combat; however, they are treated as the appropriate command level zero unit for all other purposes.
Otherwise they are normal Level 0 units for all intents and purposes. This means that you can deal damage to them and rout them just as a normal plastic unit. The tokens even have two different sides. One with a black background (unrouted) and one with a red background (routed). Routing them does not automatically remove them. You have to deal enough damage to them in order to destroy them. Otherwise they will remain until the end of the combat.