Red hot chili peppers: Pretty little ditty

OK I have major problem with the right hand in the melody as shown after the 8th min of Dman's Vid:

I see the pattern G-D-A no prob, but like other songs like "IF" by RHCP or "Seeman" by Rammstein, I can't get it work with my right hand and WALKING. Tried other methods, like guitar fingerpicking but I dont seem to get it right. If I want to walk this G-D-A-G-D-A etc pattern with 2 fingers, how do I keep the rhythm?

Something is going wrong I guess because I 'lose' my fingers and ALL of the melody. Any ideas or any tutorials about the specific bass technique?

Thank yas!