Help needed - adjusting door on Briggs 4 door

[67sunroof]

I could use some expert advice on how to adjust a sagging and "bulging" door on my 1928 Briggs Fordor.
I hate to undertake this without some guidance. As you can see from the photos, the door sags at the top
at an angle and will not fully close flush at the bottom. The bottom edge just barely clears the step plate.

If you have some tips please e-mail me at sosuttle@aol.com or even call 505 828 2165.

Any help greatly appreciated.