there is a thread in 'general instruction' about scales, you will find it easy enough.
then after you have learnt you will see that all he did in that particular bar is: played the root note, then done a slide from the major 3rd to the 5th, before going to the octave twice, back to the 5th, octave, 5th, and root.
may sound like jiberish, but soon enough you will think that is remarkably simple.
i haven't played for that long (1 and a bit years) but iv found learning the scales is something that can easily make you sound good on bass even if you dont have a great idea of what you are doing...
if you like help on other songs send me a personal message, i might try and work it out, for your sake and mine, no guarantees ill be able to get it though, i aint great.