How can I update to 8.4, when currently version 6. Do I need to upgrade to 7 first

What iPad generation do you have? You have to install iOS 8.4 you can't update to iOS 7. If you have the first generation iPad you can't update past iOS 5. -AJ

Hello Charles kimbell,

If you are unable to update over Wi-Fi you can always try to update through iTunes. Otherwise what kind of issues are you encountering when you try to update? Also are there any errors? If you are just needing assistance updating check out the link below.

https://support.apple.com/en-us/HT204204

IF it won't install over the air you need to connect to a computer and do it through a usb cable and iTunes.

FFrom apple website:

Update your device using iTunes

If you can’t update wirelessly, or if you want to update with iTunes, follow these steps:

1. Install the latest version of iTuneson your computer.
2. Plug in your device to your computer.
3. In iTunes, select your device.
4. In the Summary pane, click Check for Update.
   
5. Click Download and Update.

If you don't have enough free space to update using iTunes, you'll need to delete content manually from your device.

Update the iOS software on your iPhone, iPad, and iPod touch - Apple Support

If the over the air update says to install than it may already be downloaded. Be sure that you have at least %50 battery or that you are connected to a charger as this is required to install iOS 8.4. Otherwise AJ397 is right and you will have to connect to iTunes to update. Follow the link in my first response for steps on how to update through iTunes.

No problem, if you have any other questions feel free to ask.

Hi

What model ipad do you have older ipads cannot be updated to 8.4 ios

Ie ipad 1

Cheers

Brian uk