Hopefully this will help?
If the board is densely populated I use the smallest nozzle i have and around 360-380C/680-716F. Circle the IC about 2.5cm away.
If that fails i run a fine wire under the legs on one side of the IC and user an iron to melt the solder as i gently pull the wire up, lifting the pins as it goes.
If that fails, and it rarely does, i cut the legs from the IC package with a scalpel and remove the remains with an iron.
RR