President Bush plans to overhaul his economic team for the second time in two years and wants to tap prominent figures outside the administration to help sell rewrites of Social Security and the tax laws to Congress and the country, White House aides and advisers said over the weekend. The aides said the replacement of four of the five top economic officials -- including the Treasury and Commerce secretaries, with only budget director Joshua B. Bolten likely to remain -- is part of Bush's preparation for sending Congress an ambitious second-term domestic agenda.