Solder the resistor into place. Hold the tip of the iron so that it touches where the lead and the pad meet. Hold it there for about 4 seconds, and then feed a small amount of solder into the joint where the lead meets the pad. Hold the iron there for a few more seconds, then remove it.

Finally, clip the excess leads off the resistor.

Repeat these steps to remove the 100k resistor and replace it with the 10k resistor.