If your pad is solidly connected to the plane, that's normal. Your EDA
software should have a way to make a thermal barrier around the pad,
which not only keeps the heat where it's supposed to be, but also the
solder:
http://www.delorie.com/pcb/docs/gs/gs.html#thermalOtherwise, the trick will be to (1) flux the lead, and (2) apply heat to
both the lead and pin while applying solder to the other side of the ∗lead∗.