Have not done rear Catera brakes. Two suggestions:
You need a shop manual like _yesterday_!!
and
Cross post your question here:
http://autos.groups.yahoo.com/group/...wners/messages
You will have to join if you have not already done so. There is a Catera mechanic (it's how he makes his living) in that group who might give you some help.
Final counsel:
Do not force anything. You can do some real damage and run up the $$$$$ very fast. Wait until you know for certain what you are doing and know how the thing goes together.
Good luck!