Slapping Multiple notes at once?

[Sir Markus]

Hey guys I just bought The Brown album by primus and I heard a song called shake hands with beef, so I looked up a tab (http://www.911tabs.com/link/?3625507) for it and it had
G|-----------------------|
D|-8\7------8-\7-------|
A|-8\7----8---\7-------|
D|-8\7--8-----\7-------|

s s p p

G|-----------------------------------7-----------|
D|-8\7------8-\7--5\4------5-\4--7-----------|
A|-8\7----8---\7--5\4----5---\4--5-----------|
D|-8\7--8-----\7--5\4--5-----\4--------------|

s s p p s s p p f

I have no idea how I am ment to slap 3 notes at once can someone please explain to me, thanks a bunch.

[Bakerman]

The part isn't played like that, but to get a slap sound on multiple notes I'd try swatting them with extended fingers if getting the thumb across all strings wasn't working. Here's what he's doing in SHWB; 3rd/4th string always popped and 5th/6th string slapped.