#9 is probably the only wire that's going to give you any trouble (it kicked my ass
). Flux IS included in rosin-core solder, but these pads are so small that you really can't add solder directly to the area (I couldn't anyway).
As I'm sure you've heard, use smaller wire than what Lik-Sang gives you. I would just cut a piece of the smaller wire about 6-8 inches long and then later, after the motherboard is back in the case, you can solder the #9 wire lik-sang gives you to the smaller guage wire you soldered to the #9 pad. That way, you don't have to worry as much about accidentally ripping the pad off while you're trying to get everything crammed back in the case.
In retrospect, I think the best way to do #9 is to flux the pad with a paperclip or something. Cut back the insulation about 1mm from the end of the wire and tin it. Then tape it securely to the motherboard about an inch from the pad. Touch the wire to the pad, and heat(for a second--maybe two). The solder should flow to the fluxed pad. This is where the flux helps. Without it, the solder will not flow to the pad as easily.
The important part is NOT to move the wire at all-- especially after the solder takes hold. That pad is just barely connected to the board. Any movement can break it lose--especially after you've been heating it. If I was doing it again, I would hotmelt glue or superglue the wire to the board to keep it from moving.
This isn't the same spot on the motherboard, but it's a good example of what you want your finished connection to look like: