First of all: Create a folder somewhere easily accessible and put in the ConvertData_Rebelion and msvcr80.dll files (I put my files at C:\ConvertData because it is a short path).

1: After having created this folder, in the Search bar (in Windows' Start menu), type cmd and press the enter key.
2: Navigate to this folder you created by typing: cd C:\ConvertData and pressing the enter key.
3: For entity file conversion from BIN to TXT copy and paste the files you wish to convert from the Rebellion game folder into the folder you created.
4: In the command prompt type ConvertData_Rebellion entity *file name(case sensitive)*.entity *file name(case sensitive)*.entity txt and press the enter key (don't enter the asterisks (*'s) in the prompt).
5: You can now edit the files and use them as a mod.

Hope that helps!