Unsolder large TO-220 or TO-247 packages
The three legged components can pose a challenge during removal especially if they are soldered into multilayered boards with metalized vias. Heat from the soldering iron will quickly spread away and suction desoldering tool (vacuum sucker) won't able to clear the molten solder inside the vias.

My method of getting those three legged dead components out from the board is by using a heat spreader. Use a half inch length of 2.5mm^2 copper wire to bridge all three soldered point and wet it with abundant solder. Heat spreads quickly through that copper wire and melts the three points evenly.

While having them melted, hold the board strategically and gently pull out the dead piece from bottom. Once the component is fully removed, clear the vias using sucker.