Help for editing the SWF files. and modify allready existing mod to prefferences (1 Viewer)

[cumlord123]

I want to find out how to open the SWF files for allready exisitng mods and edit them by adding my own (in this case) voicelines.
I tried searching far and wide, but I am blank and new to this so any help is appriciated.

I do not know what programs to use, I do not know how to edit them either, I figured I would learn as I go.
Thank you