Pics are not the best but simply mask up 1 or 2 mm around window and frame then seal with polyurethane sealant (toolstation £4 a tube )smooth with wet finger then pull off the tapes -eliminating it leaking from outside leaving only condensation if its wet inside
Its not going to damage the door as it is dense foam with alloy outer skin and plastic inner skin. Try get it dry (outside) pry the rubber away and inject sealant behind it.
Mask around it like Terry said and it will be less messy.
TWO person job ideally, one prying the rubber away one applying sealant