Well, here is the answer to my own question. First, get a repair manual from Whirlpool for its "duet" front loading washer Model Nos. GHW9100L/GHW9200L. It is no charge in pdf at "Consumers Services Technical Education Group" Job Aid part no. 8178076. It is quite complete.
Baffles are available for purchase in a set of three p/n 8181669. Even though only one may be broken it is best to replace all three.
I removed the drum and basket assembly completely but found out it not necessary.
Go through the parts access steps to remove the top panel from the washer. Locate the basket access hole in the top front of the drum. This is for access to the single SM screw that secures the baffle into place. (In my case there were no screws in any baffle.)
To remove: Rotate the drum until the baffle screw is visible through the access hole. Remove the screw and with a rubber hammer lightly tap the baffle toward the rear. It is held in place with moulded slip fittings and will fall out.
To replace: Place the new baffle toward the rear and set it flat and firmly on the basket surface. Slide it forward until the baffle screw hole is aligned with the basket screw hole. It should lightly snap into place. Check to make sure the baffle is flat against the basket along its full length. Insert the screw and tighten snugly. The screw is only to keep the baffle from sliding out of positiion. Overtightening will strip the plastic baffle.
This is my first trip into the washer and, although access is easy enough, hope it's my last.
Bill, January 2007