I found that the radio shack bulb desoldering iron is great for buttons.
I used to use solder wick, but now I prefer this. Remember you need to tin the tip of the iron before use (melt some solder on the tip once it gets hot enough, like oil in a pan),
Also for some tough solder joints, add a bit of fresh solder to the joint, the flux will help the old solder melt quicker.
You are squeezing the bulb before putting the iron on the joint and spraying the sucked up solder into a trash bin or something right?
The iron with the bulb on it is only 9.99 can't go wrong.