I just changed the body-side driver door seal on my MX. Mine split on the bottom edge, probably because I rubbed my legs there getting out for years. It’s pretty easy, but there is one trick I learned from a Tesla SC tech: there’s a seam in the gasket at the front of the door opening. Put some tape on the plastic next to the gasket seam and make a pencil mark locating the seam. Start the new gasket with its seam at the mark, then press the new gasket into place moving away from the seam.
I’ll make a video of this if there’s interest.