Oof, the no-lead type of chips with the pads underneath and nothing exposed for you to look at... Never done one myself, but I think a hotplate for solder reflow is the best option. Maybe pre-tin the pads and sop up excess solder with wick, carefully place the chip on the pads (with good magnification and a steady hand/good tweezers) while heating the board on a hotplate.
Like what they talk about here: Reflow Skillet - SparkFun Electronics
OTOH, I'm not sure but maybe you could get by with long PCB traces coming out, pre-tinned with solder, add flux before laying down the chip and try applying the soldering iron tip to the traces hoping the solder will reflow underneath the pads with the help of the flux (without needing a hotplate).