Door Seal on Trillium

[NitKnit]

Hello fellow RV'ers. Clearly need to re-do the seal on my door and the door frame, as well as the metal 'stoop' at the bottom.

Is this an easy replacement? Special goop to remove current seal?

I've gone to local large RV outfits and they don't sell the materials, so I assume it is at general hardware/automotive stores?

Also, one of the RV outfits told me just to move the screw hole over in order to re-attach the 'stoop' bar. Would that work?

I have more pictures, but I think we are only allowed to upload four at a time?

Thank you!

PS - Apologies for the photos being sideways. Not sure why they did that.