Newbie Creating a Map (mkgmap)

Hi, I'm following this page https://wiki.openstreetmap.org/wiki/Mkgmap/help/How_to_create_a_map tutorial. Unfortunately I don't get very far. I've installed java 1.7 on Ubuntu 12.04. I've downloaded splitter-r423.jar and us-northeast-latest.osm.pbf to ~/Project$.

I then run $ java -jar splitter-r423.jar us-northeast-latest.osm.pbf

and I get this error: Exception in thread "main" java.lang.NoClassDefFoundError: crosby/binary/file/BlockReaderAdapter at java.lang.Class.getDeclaredMethods0(Native Method) at java.lang.Class.privateGetDeclaredMethods(Class.java:2615) at java.lang.Class.getMethod0(Class.java:2856) at java.lang.Class.getMethod(Class.java:1668) at sun.launcher.LauncherHelper.getMainMethod(LauncherHelper.java:494) at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:486) Caused by: java.lang.ClassNotFoundException: crosby.binary.file.BlockReaderAdapter at java.net.URLClassLoader$1.run(URLClassLoader.java:366) at java.net.URLClassLoader$1.run(URLClassLoader.java:355) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:354) at java.lang.ClassLoader.loadClass(ClassLoader.java:425) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) at java.lang.ClassLoader.loadClass(ClassLoader.java:358) ... 6 more I suspect it has to do with classpath but I can't fix it. Could you help? Thank You