How can i update ipad2

You do not have iOS 5 on your iPad so you have to update by using a computer via the latest version of iTunes. You can connect the iPad to your computer and launch iTunes. Select the iPad on the left side under the devices heading. Click on the Summary Tab on the right. Click on Check for Update.

After you update to iOS 5 or later, you will have Software Update in you settings and can update via WiFi OTA. You will be updating to iOS 6.0.1 now.

How to update to iOS 5 or later.

http://support.apple.com/kb/HT4972

Connect it to the computer you sync with, in iTunes click on the name of your iPad under DEVICES, move right to the Summary tab and click the Update button.

Since you have iOS 4 you will need to connect it via USB to a computer with installed iTunes on it.

TZ

iOS 5: Updating your device to iOS 5 or Later

http://support.apple.com/kb/HT4972

How to install iOS 6

http://www.macworld.com/article/2010061/hands-on-with-ios-6-installation.html

iOS: How to update your iPhone, iPad, or iPod touch

http://support.apple.com/kb/HT4623

If you are currently running an iOS lower than 5.0, connect the iPad to the computer, open iTunes. Then select the iPad under the Devices heading on the left, click on the Summary tab and then click on Check for Update.

Tip - If connected to your computer, you may need to disable your firewall and anitvirus software temporarily. Then download and install the iOS update. Be sure and backup your iPad before the iOS update. After you update to iOS 6.x, the next update can be installed via wifi (i.e., not connected to your computer).

 Cheers, Tom 😉