Grab center medallion cap and twist counter clockwise while holding the horn ring and steering wheel from turning.
On 69 Dart with padded horn ring
Place a small screwdriver between medallion and horn ring on driver's side of medallion (9:00 position) and pry up.
Go easy and you might want to place some protection between the padded horn ring and the screwdriver.
There is a slot on the passenger side (3:00 position) of the horn ring
and a tab on the medallion
to index it on reinstallation.
Thanks to CRUZE 418 for the 69 Dart padded horn ring photos
If you have other horn ring photos form other years and a procedure, PM me and I will add it to this How To.