The resulting file (likely a .png or specific data file) usually needs to be placed into a designated "User" or "Characters" folder within the target application's directory to be used. To give you a better write-up, could you let me know:

You will need a file archiver like 7-Zip or WinRAR to extract the contents of the .7z file.

are you planning to use this with (e.g., Koikatsu, HoneySelect, a 3D modeling tool)? Once I know, I can tell you exactly where to put it!