Turn off the power to the circuit that powers the baseboard heater. Do this by locating the appropriate breaker within the main service box of your house and switching it to "off."
Remove the front cover from the baseboard heater. The front cover is clipped onto the body of the heater. Gently pry it away from the heater from the bottom and it will release.
Back off the screws that go through the back plate of the heater and into the wooden baseboard behind it. After the screws are removed, you'll be able to move the baseboard away from the wall, but it will still be connected by its wire.
Disconnect the wires from the baseboard heater. Untwist them from their connections with a pair of needle nose pliers. Gently pull the baseboard heater away from the wire and feed the wire out through the hole in the side of the heater.
Screw wire nuts onto the ends of the white and black wires for safety. Bend the wire upward and tape it to the wall so it's out of the way of the flooring work.