Okay. Here's my recommendation. It's a little methodical, but it will give you flexibility if you plan to play a lot of RTW mods. As with any step-by-step instructions, read through to the end before doing.

1) Download the 1.3 and the 1.5 patch from http://www.sega.com/support/support....port_romepatch
2) Completely uninstall RTW from your system
3) Install RTW, but instead of the default directory rename it something like "(drive):\(path)\RTW Core\" - for example, "C:\Games\RTW Core\" - do not install it into a previously created RTW directory!
4) Install the 1.3 patch
5) Install the 1.5 patch
6) Go to the directory where you installed RTW
7) Copy the "RTW Core" directory and then paste it; wait for however long it takes to finish. You should now have "Copy of RTW Core" in the same directory as "RTW Core".
8) Rename "Copy of RTW Core" to "RTW-EB 0.8" or whatever you want to call it
9) Install EB 0.8. When the patch asks where to put it, direct it to your "RTW-EB 0.8" directory.
10) Play!

This will keep a clean copy of RTW 1.5 on your computer in the "RTW Core" directory. Anytime you want to install a new mod, copy that RTW Core directory and rename it (ie "RTW-RTR PE", "RTW-TFT", etc). The only limitation is that the mod will need to run on patch 1.5, so check the mod requirements before you download.

Good luck!