How do you update the Arduino IDE?
On Windows and Mac your Arduino sketches and custom libraries are placed in your Documents folder by default. Most importantly, they are outside of the program directory. I'm almost positive the same goes for Linux.

Mac
You can upgrade it just like any other Mac application. Download and mount the .dmg, then drag and drop it to your Applications folder, replacing the old Arduino.app.

Windows &amp; Linux
The Arduino IDE doesn't install to any specific location. It's just a standalone folder. To update, just delete your old folder you previously extracted with the new one. If you're on Linux and you installed Arduino through your package manager you may be able to update it through that venue. The Arduino Playground attempts to cover most popular distributions.

Drivers
The Arduino changelog should note if there's an update to these. To update the drivers you'll have to perform the driver installation operation again. Instructions for: Windows (drivers required) and Mac (drivers only required for using older, pre-Uno boards). On Linux, if you're using kernel version 2.6 or greater (verify with uname -r) then there are no drivers for you to install. You'll need to remove the brltty application if it exists on your system.