updated INSTALL doc

Author: hltbra

INSTALL

@@ -1,15 +1,15 @@
 To install should_dsl you just need to have setuptools installed (it's a dependency).
 
 There is just a little step to install should_dsl, and it is:
-$ python setup.py install # maybe you must be root
+$ [sudo] python setup.py install
 
 Now you can use should_dsl!
 
-If you don't have setuptools installed or don't want to download it, you can just copy the should_dsl.py file to your python site-packages directory.
-For example:
-$ cp should_dsl.py /usr/lib/python2.5/lib/site-packages
+You can use PyPI and install through pip or easy_install:
+$ [sudo] pip install should-dsl
 
-Or you can choose to install it by easy_install:
-$ easy_install should-dsl # maybe as root
+or
+
+$ [sudo] easy_install should-dsl
 
 Enjoy it!