For all verbs in Spanish there is just one way of forming the imperative (affirmative commands) of vosotros. Regardless of any irregularity that the verb might have in any other tense, the vosotros form of the imperative will always be formed this way:
1. Take the infinitive form of the verb (e.g hablar)
2. Drop the final -r (habla-)
3. Add -d (hablad)
Have a look and listen to some examples of totally regular verbs:
Have a look and listen to some examples of stem-changing verbs:
See also Conjugate in El Imperativo with reflexive pronouns (affirmative commands) for a more advanced lesson on the imperative with reflexive verbs.