They'll spend the next six weeks running miles of wires through the building, and building hospitality and media suites.
When all is built, John McCain will accept the Republican Party's nomination a few feet from where the Minnesota Wild and their opponents usually sit during hockey games.
Workers got right to work Monday morning, after a brief photo-op where the Xcel's general manager ceremoniously handed over the keys to the arena to the host committee.
The aim is to make the space one that even hockey fans and concertgoers won't recognize. While workers started unloading trucks, phone lines started going in, and seats started coming out.
"As I understand it we're going to cover the seats, take a bunch of seats out and build a stage," said Tom Rice, a union carpenter from Local 87, one of the nearly 600 laborers who will transform the space. "Actually I have no idea, we've never done anything this large before."
Each luxury suite in the arena will become a studio for media networks, designed to each outlet's liking and budget. Crews will take out seats in front of each suite, so that the studios extend out and tilt downward. That will allow reporters to do live shots with the floor activity behind them.
Miles of phone and Internet cables are being installed, and that doesn't include all the other cable that media outlets will bring for themselves.
The Republican Party and its general contractor will have exclusive access to the arena through the convention, meaning even the Wild's merchandise store will be emptied so it can be turned into a hospitality suite.
"They need every inch of space," said Kathy O'Connor, an Xcel Energy Center spokeswoman.
The arena would normally host four to six events -- mostly concerts -- during this span, she said.
The host committee isn't saying how much it's paying to rent the Xcel for the eight weeks.
Mike Miller is in charge of setting up his 10th Republican convention, dating back to Miami Beach in 1972. He says the Xcel is among the easiest sites he's worked with.
"The concourses are very wide, the concourses are open into the bowl so we can build things into that -- media positions, hospitality positions," he told reporters, while standing on a busy loading dock. "And you have room in the concourses to do things with. Madison Square Garden's hallways weren't even half this. There was no openness into the bowl; there were walls and everything."
Organizers of the 2004 Republican Convention in New York also had to raise the floor at Madison Square Garden to add space underneath for offices.
Miller says the goal is to have everything in place for a dry run on Aug. 29, three days before the Republican convention starts.
Once it's over, crews will have two weeks to get the arena back to its usual state. The host committee will return the Xcel to its managers just six days before the Minnesota Wild are scheduled to play their first home pre-season game.
The event will be Minnesota's first national political convention since 1892.