Yes, the first sensible thing to do would be to ask calmly else you are going to look like an idiot to us. And it is BAD.
It is quite easy for anyone with average intelligence.
When you have downloaded the file (DSL or beetlebros pack), you will see it is a .RAR file. You need WinRAR first if you don't have it.
Create a new folder anywhere, decompress your downloaded RAR file in that folder, then copy the files that were just created into the game's (normally Program Files/Infogrames/Robot Arena 2 folder. You will want to overwrite the Components, AI, UI folders, so click Yes when the computer asks you to overwrite.
(It is recommended that you make a backup of your original Stock game first, therefore do a copy of your original game, rename it and copy the decompressed files in that copy's folder)
