"Are we going to fight this bear or what?"
"Let's do it to it."

can be used alone: "do it to it"

"Go do it to it nigga."

Hell yeah we're going out tonight; we're gonna do it to it.

question: "hey wanna watcha movie"
response: "let's do it to it"

we did the do

And you're standing at the chemist in Boots
Coughing up your guts like you're at deaths door
All this for a packet of Do-Dos