Select, complete, and sign the appropriate form from among the following three alternative Petition for Letters forms, depending on: If Decedent left a Will:. This procedure allows someone legally entitled to inherit a decedent's personal property to get that property without going through probate.In Washington, laws concerning probate, wills, trusts and guardianship are found in Title 11 of the Revised Code of Washington (RCW). To find information and forms regarding the probate process please visit Washington Probate Forms , King County Probates or the Pierce County Law Library. The purpose of most probate proceedings, such as an Adjudication Proceeding, is to obtain a Court Order that you may deliver to a transfer agent. The Clerk's Office offers a will repository service which allows for the filing of an original will with the court, under seal, before the death of a testator.