Well first make a copy of your BaDIK folder, should always have an vanilla one, so you dont mess things up and have to redownload the game.
Then you'll need
Unren , version Unren-v.0.11-old(v2) works, I have not yet checked the other version. So download that one, unzip it and put it into your BaDIK main folder.
Run it, choose option 1, press N, wait for it to finish, close it, run it again and choose option 2, wait again and then you can close it.
After that you'll have 2 versions of every script, a compiled *.rpyc and a decompiled *.rpy. The *.rpy files are clear text, so you can read them.