How to change certain body guards skins?

Hello. I would have a question regarding what do I need to do if I want to change Epeiros and Koinon Hellenos bodyguards skins.

Epeiros as Seleucid body guard skins and Koinon Hellenos to Ptolemaioi's skins. Also how do I make Epeiros being able to recruit Hippeis same way as Koinon Hellenos?

If you have spare time and want to help me out a bit. You could include modified files and upload .rar or something here.

I know how to mod some stuff in RTW but it is always time taking and stressful for me :laugh4:

Thanks ahead for people who can help me out with this.