colorado
If you have a dispute over values worth not more than $7500, you may sue in Colorado Small Claims Court.
If the value is worth more than $7500, you can also waive the excess value and stay in that court, though you will not be able to collect that excess amount (and no, you can't cheat by breaking it into multiple small claims).
If the dispute value is significantly more than this, or you do not wish to waive, you need a lawyer who is certified and qualified according to the regulations for your state.
If a contract doesn’t specify a time for something to be done, it must be done in a reasonable time.