A really tiny soldering iron?? :)
There are a few ways to handle it. Myself, I use a small amount of solder paste (like put it on with a tip of an Xacto blade), position the chip so each lead makes decent contact with the solderpaste, and while holding the part down, run a solder gun down the pins.
If you overdid the paste and have bridging between pins, use some solder wick and flux to clean it up. Check your work out with magnifying lenses to make sure you are not shorted.
If you are going to regularly do small smd's, you might check out a hot air rework station. It makes life easier.
If you don't have any paste, you can also flux the pads, use solder to make small beds on each pad, flux the leads of the chip and set it on the pads and run the solder iron over them too.