Soldering advice needed - Solder paste or flux?

Hi out there!

I have acquired an iPhone 5, which was in a "connect to iTunes" restore loop. After some troubleshooting, I established that a few components had been knocked of the logicboard, which caused the restore loop.

The two components in question are shown on the following picture: https://d3nevzfk7ii3be.cloudfront.net/ig...

The small signal mosfet designated "Q3" and the low-power dual buffer designated "U3". The two packages are extremely small (the U3 is 1mm x 0.9mm and has 6 leaders)

I have bought a small hot air reflow station, but I can't seem to establish weather I should use a small amount of soldering paste and reflow the IC's, or weather I should apply a small amount of solder to the solderingpads on the logicboard, use flux paste and then reflow the IC onto the board - to ensure that no shorts/bridging will occur.

Anyone with some soldering experience that can advice me please?