Clean build in Xcode / Snow Leopard

I am new to OSX and stsarting to use XCode. Here I found the clean build options when working on my C++ project, but both are disabled, how can I use or activate them?

Thanks

How do I do a clean build in Xcode?

To clean the build folder you can use the shortcut Command+Option+Shift+K or Menu Bar → Product → Hold Option Key → Clean build Folder .

What is Xcode build tool?

xcodebuild is a command-line tool that allows you to perform build, query, analyze, test, and archive operations on your Xcode projects and workspaces from the command line. It operates on one or more targets contained in your project, or a scheme contained in your project or workspace.

Just do a Command-Option-Shift-K this should clean the project.