Legal Question in Wills and Trusts in Missouri

Your question is not clear. Do you mean a will that was drafted five years ago, or a will for someone who died 5 years ago? If the latter, which I assume, then you simply need to go to the probate court where the will was administered. They are public records once admitted to probate. If you were a beneficiary under the will, you should have received notice long ago.

You can go to the Probate Court in the County where the decedent died, or owned real estate when living. You should be able to do a search for any Will (or have a clerk do the search) with the full name and possibly birth date of the decedent.