When you open a Released object in Pro/E and try to modify it, 9.1 prompts you to Check Out, Make Read Only, or Continue.
If you select Continue, you will be able to make changes without checking-out the object, and you will be able to save them to your Workspace, but you won't be able to check those changes in to Commonspace (without some wrangling).
The modified objects will have a symbol next to them in your Workspace that says "Modifications not eligible for Upload".
To "Update" the objects (in 3.4 speak), just re-add them and un-check "Reuse content in target workspace".
Does that answer your question, or are you wondering how to actually set up permissions and release states?
