Updating subtree directions

Author: Toni Klopfenstein

Libraries/README.MD

@@ -20,9 +20,8 @@ Distributed as-is; no warranty is given.
 - Your friends at SparkFun.
 
 
+Update Library Instructions:
+----------------------------
+To get the most up-to-date version of the library, you must run the following git subtree commands. 
 
-BUILD INSTRUCTIONS:
-
-$git subtree add -P <DIRECTORY NAME> --squash <git repo URL> <ref>
-
-$git subtree pull -P <DIRECTORY NAME> --squash <git repo URL> <ref>
+$git subtree pull -P Libraries/Arduino --squash https://github.com/sparkfun/SparkFun_SX1509_Arduino_Library.git master