Step 1:- Simple way to obtain his phone first and then quickly go to the File Manager
Step 2:- Now the open whats App floder and click Database
Step 3:- Here you'll find the last 7 days, which history database name is "msgstore-date.db.crypt8" and send these data base via bluetooth or SHAREit.
Step 4:- then how to read database file (go--> recoverymessage.com) and click " select SQLite File"
Step 5:- finaly you are able to read chat file.