For a life and medical insurance eligibility review after death, how should we handle all of this paperwork needed?

My brother in law recently passed away. He had purchased a short term major medical insurance policy less than two weeks before his hospitalization and death. He also had two life insurance policies that were less than two years old, therefore in the contestable period. The health insurance company and both life insurance companies are sending medical record release forms to see if he had pre-existing conditions. We are very confused about how we should handle all of this paperwork. All policies were in good standing at the time of his hospitalization and death, but now we're nervous that we will do something wrong and these companies will deny the claims.