This guide explains how to import the project into Eclipse so that you can actually work with the code. This guide assumes that you have actually acquired the code as explained in How to get the source code and that you have installed Eclipse and the FRC toolchains. Eclipse can be installed by simply downloading and running the Botsmiths Eclipse Auto Installer, or it can be installed manually as described in the FIRST documentation. You'll only need to install the C/C++ stuff, all the Java stuff except for the JDK is optional.
1. First open up your Eclipse workspace and go to File->Import...
2. Choose General->Existing Projects Into Workspace and click Next.
3. Browse to find the root directory of the project and then hit Finish.
4. This step is only required if Eclipse is giving false errors. If example projects work fine, then this step can be ignored. False errors in Eclipse can be fixed by reindexing the project. To do this, just right click the project and choose Index->Rebuild.