How to cut a projector file or swf

hi flashies

i am very new to this site …
i have a question regarding flash…i am not an advanced user of flash

the question is that i have a projector file but it was an old presentation…i now just want to delete a portion of this projectore file…

How can this be done…because i have lost the source file
Secondly there is a picture in the whole movie like a logo( an older version)…i want to hide that…how can this be done.

And if it was an swf file instead of projector file then how can i do it…

please help
thanks in advance