I mnight be doing it the crude way, but I've found the hot air attachment to my cheapy Gascat 60 (Antex) does the job nicely, altohugh its a bit small for wide SOIC28's. I have scraps of thick copper foil/sheet to mask around the chip in question, with the sides 'tapered down' a bit towards the chip so it doesn't immediately reflect the heat back up. After a few years of doing it with flux and desoldering braid, the hot air method is much more gentle on the board/chip/pads. I still use flux though!
A slow gentle circular motion over the top of the chip around 3/4" away (all depends on the size of your hot air nozzzle, and temp... mine isn't in any way temp regulated) for around 6-7 seconds, then an occasional 'nudge' with the end of a pair of tweezers. If you've got it slightly too hot the pads can easily be moved out of place. Once it's moving slightly, tweezers to gently move the IC off the pads (in the direction of the row of pins on one side) with it still flat on the board, and pull it off - the pins should be disconnected (in terms of solder) from the pads before lifting it, otherwise you could lift pads.
I pracitced a lot on old laptop motherboards, which are difficult because of the extensive copper power planes, which quickly draw heat away from the site you're trying to heat up. In which case, more air flow is needed. After that, two-sided boards become a breeze. I'm STILL surprised I haven't destroyed any chips/semi's yet. But at the start, I did damage some PCB's..