01. Download minecraftserver.jar for 1.2.3 or 1.2.4 from minecraft.net (you should have done this before, because theres only a link for 1.2.5 version)
02. Download ModloaderMP for Server (link in IC² public releases)
03. Download the actual Minecraft Forge for Server (link in IC² public releases)
04. Download IC²-Server
05. Extract the minecraftserver.jar with WinRAR or something similar
06. DO NOT remove the META-INF
07. Put ModloaderMP-Files into the Server-jar
08. Put Forge-Files into the Server-jar
09. Put anything back into a .zip
10. rename the minecraftserver.zip to minecraftserver.jar
11. Run the Server like described on minecraft.net via Commandprompt to generate all the Files and Folders
12. Put IC²-Server-jarfile into "mods"-folder
13. Run the Server again
14. Learn more English
15. Connect to it and you're finished
Is that all or did i forgot something?