At work we’ve had a running joke of having one task every week be given a title that is a variation of “kick some ass”* and I’m running out of euphemisms. Here’s what we’ve used so far:
Kick some ass
Give it hell
Storm the castle
Open a can of whoop-ass
Release the hounds
I know you can come up with more! Feel free to be creative.
I believe Terry Pratchett was fond of the “prod buttock” expression.
Administer a beat-down
Bust some heads
Dot that i (eye)
Spank it like a redheaded stepchild
Take it to the house
Sock it to 'em
Show 'em what for
Crack some skulls Chiklis style
Go all Chuck Norris on it.
Send in the SEALS.
Have [insert Sopranos goon] fix it.
Nuke it 'til it glows.
And for really tough problems:
Nuke it 'til it glows … so you can shoot it in the dark.
Blow their doors off. (or just Blow Doors!)
Going Chicxulub.
Off with their heads!!
Put a WHAMMO on it.
Lay down the smackdown.
Stomp their ass into a mudhole. (Oops, my redneck’s showin’ :o 
)
Go medieval.
Murderize it.
Put it in deep doo-doo.
Curb stomp it.
Throw it out on its ass.
Get it behind the 8 ball.
Leave it black and blue.
Introduce it to a whole new level of physical pain.
(Slight hijack…I think this is from a movie… “I am going to introduce you to a whole new level of physical pain.” Can anyone name the movie?)
This resembles:
Take down names
Kill people and break things
My personal fave is “grab it by the nuts and drag it up and down the stairs until it begs for mercy.”
Although it occurs to me this ain’t much of a euphemism.
Turn it up to eleven.
Meet him by the bicycle rack at recess.
Meet him by the bicycle rack at recess and I’m bringing my lunch box!
Win his Heart And Mind.
Have an open and forthcoming discussion.
Come to a mutual agreement.
Point out some things he overlooked.
Reason with him.
Comfort his widow.
Beat some butt
Knock the livin’ daylights out of
I will strike down upon thee with great vengeance and furious anger.
Give a bunch of fives.
Get out there and knock it out of the park. Or maybe, Hit a homer.
Give it all you’ve got!
Show them who’s boss.
Thump it upside the head.
<sings>Kill the wabbit! Kill the wabbit!</singing>
Make him an offer he can’t refuse.