Renovate old roof insulation?

Hello,

we are currently starting to renovate our house, built in 1967. The attic is to be converted, the insulation is (see photo) already in place, but we have some questions for people who are familiar with the subject.
-the old vapor barrier or vapor retarder is brittle in several places due to UV radiation. This should definitely be replaced, right?
-the insulation consists of mineral wool, which was certainly installed before 1996. Should this also be replaced for health reasons or for building physics reasons (insulation value)? Possibly moisture has already penetrated due to the damaged foil.
Who has experience and can give tips on how to proceed.

Moisture is the natural enemy of mineral wool. A vapor barrier must always be absolutely airtight. If you remove it and the clamping fleece comes loose, the decision is made. For cost reasons, it probably makes sense to replace everything completely. It is best to have it inspected by a professional. For example, an energy consultant. You can find instructions for interior roof insulation here:

Links removed by mod