The easy answer is - don't.
CAD systems aren't really designed to do a good job of maintaining a manufacturer list. That's database kind of work. Keep a separate database linking your part number to the approved manufacturer's numbers. So if you need to change manufacturer information on the 1004473 part, you change it in your databse only, not in the 2 dozen schematics that use the part. Depending on your software, you can push a BOM from the schematic, or pull manufacturer data into a BOM. It's also a handy place to keep datasheets.