Capture: Update part from spreadsheet?

I work for an IC manufacturer.  For a new IC, I created a schematic symbol using Design->New Part from Spreadsheet.  After cleaning up the symbol, I used it in a preliminary schematic.  Now, the IC and packaging people have changed the pin out (every pin needs to be renumbered). 

I updated my documentation (a spreadsheet) and I went to cut and paste the changes into the Capture spreadsheet for the schematic symbol, but I can't find a way to get to such a spreadsheet. 

Where is the corresponding Update Part from Spreadsheet?

What I want: 

• An easy way to make mass changes (such as changing the pin numbers or other pin properties) to a schematic symbol.
• When updating/replacing the old schematic symbol, the new schematic symbol should not change the functional connectivity of the schematic.  In other words, the pin positions on the schematic symbol cannot change.

Any one know of a way to do something like this?

Thinking about this some more, I realize that there are some difficulties in doing what I want; some restrictions may be necessary.

One way which might work, is to bring up the original spreadsheet, with the pins in the original order.  These spreadsheet pins are linked to the pins on the symbol.  You could then change the pin numbers, names, or other properties of the pins en masse (even using cut and paste from an external spreadsheet).  After saving and exiting the spreadsheet entry form, the schematic symbol will be updated.  This is equivalent to using the Pin Properties editor in Part Editor, but working on a large number of pins at once.

This time, I ended up doing them one at a time, by hand, in the Pin Properties editor.

Any better ideas for the future?

Thanks.