This is really simple!!
--------------------------------
--------------------------------
--------------------------------
--------------------------------
-7-7-5-7------------------------
----------7-6-5-0-3-0-----------         x2

--------------------------------
--------------------------------
--------------------------------
-7-7-5-7------------------------
----------7-6-5-0-3-0-----------
--------------------------------         x2

(repeat first riff again)


change around the amount of each riff to suit you,

have fun!