Legal analysis: According to the relevant laws and regulations, you can go to the handwriting appraisal institution established by the court for appraisal through the documentary evidence and documents written by the parties before their death. In order to improve the accuracy of the appraisal, please bring as many documents as possible during the appraisal. Fingerprint identification, you can go to the local public security organ to inquire whether the parties had fingerprint information in the public security organ before their death. If you don't, you need to bring the articles used by the parties and the articles that you have the most contact with to the forensic appraisal institution of the local public security organ to apply for fingerprint identification.

Legal basis: People's Republic of China (PRC) Civil Procedure Law.

Article 76 A party may apply to a people's court for an appraisal of the specific circumstances of finding out the facts. Where a party applies for authentication, a qualified appraiser shall be determined by both parties through consultation; if negotiation fails, it shall be designated by the people's court. If the parties concerned do not apply for identification, and the people's court considers it necessary to identify specialized issues, it shall entrust a qualified appraiser for identification.

Article 77 An appraiser has the right to know the case materials needed for appraisal, and may ask the parties and witnesses when necessary. The appraiser shall put forward written appraisal opinions and sign or seal the appraisal book.