Have you done one recently?
I used to do it for a living. Open door, loosen screws behind gasket lip. pull off gasket. Slide new gasket lip behind inner retainer. Tighten screws. Use heat gun to remove wrinkles.
Not anymore. Doors w/ urethane insulation (most newer models) have to be taken off the cabinet. Then lay them on a flat surface, table etc. Remove all the screws, remove old gasket, reverse procedure to install new gasket.
Very much more difficult than older models. I've done one, that was enough.
I haven’t ever done one, but as it’s an older model, I assume it would be easier..of course, it’s up to the person if she’s willing to try. She’s trying to save money..the gasket/seal isn’t that expensive..But I assume I’m correct that it could be the cause of her problem..