This slap line appears more complicated than it actually is; if you slow it down and play it with hammer-ons on the indicated notes, you'll see what I mean.

The first sixteenth note of each group is an open string. Strike any open strings in the line with your thumb.

The second note of each group should be hammered on with the left hand. The highest note in each group of 16th notes is pulled/plucked with the right hand, so each note is articulated when the string strikes the neck. The exception to this is at the end of measures 3 and 4; these are simply a pair of hammer-ons on the upper strings.

This line can be played fingerstyle -- even on fretless -- but it really comes into its own using slap style.