Well, an SOT23-3/5/6 shouldn't pose a problem to either a soldering iron or hot-air. Preheating the PCB will further reduce resistance. As written before - don't put too much stress on the pads. It is also good to know whether the assembler used glue for that component.
Anyways, since it is Friday, I thought I might share an old report of a prototype assembly session, where I screwed up royally. In many cases the PCB and the surrounding components are more valuable than the offending component. If a mill router is at hand, there is a way that looks dramatic, but actually puts little stress on the board.
Just mill the component off the board and remove the remaining pins one by one with a soldering iron. It doesn't matter if the SMD/THT-pin is connected to one or more heat sinking planes. I have successfully used this method to remove THT-pins that where connected to three large power planes. Might require pre-heating, though.