You are still not helping us to help you. I still don't know what specifically you are having trouble with - how much you know and have achieved, where you are stuck, and how much you don't know.
- 1.32.1 is the current editor version. There is no 1.31 patch for either that I am aware of.
- Editor 1.32.1 is only compatible with version 1.21g of Civ3 for Mac.
- You download units the same anywhere. Use a browser, download them, expand them using Stuffit Expander instead of WinZip, put the folder in the /Art/units/ folder, add them to the pediaIcons.txt file, being careful to use an editor that supports DOS line endings.
- Add them into the scenario file using the editor. For that you have to find the Add patch fo rthe editor, created by Senecasax, I think.