Article 1 Section 7:
All bills for raising Revenue shall originate in the House of Representatives; but the Senate may propose or concur with Amendments as on other Bills.
The key to implementation is the establishment of these exchanges in each state. Do not fund them. Stall until the next election cycle and hope for a Republican President and Senate when repeal is more likely to pass.
Of course Republicans could just use a Pelosi tactic and just deem it so.