the .swf is the packaged flash file.. what you need to do if you want just a section of it is get the source file (.fla) and edit it in one of the macromedia suite programs that supports it.
if you don't have access to the source then you can download it using this:
http://www.justdosoft.com/flashCatcher/
also, if you don't have access to the source and don't know or have the permission of who does, you may be looking at copyright material in which case you can't use it anyway
*edit* just had a look at it.. impressive bit of flash.. but seeing as it's the official Dior site i'd guess you don't have access to the source and it's copyright.. so I'd suggest you sidestep the legal landmine and don't use it 
*/edit*