I don't have enough storage space to update my iPad mini from iOS 7 to iOS 9. As advised I have linked to MacBook Pro through Bluetooth but cannot see what the next step should be. I have little IT knowledge so answers need to be idiot proof.
Since iOS 9 is smaller in file size than iOS 7, you can just delete a few songs or podcasts or apps, whatever is taking up space, then install iOS 9, then re-download whatever you deleted. This can be a bit faster than restoring from backup, although it is still a good idea to back up your iPad!
- Back up your iOS device to iCloud and to iTunes (just in case one doesn't work).
- Open settings app and reset the device. Choose erase all content and settings.
- Then when you get the setup assistant, set this up as a new device. Skip all the optional steps (decline to sign in, set up voiceover, siri, etc... especially iCloud - skip that so you don't make a new backup the overwrites the one with your data. Also use care connecting to iTunes that you don't overwrite your backup there.
- Once the iPad is updated, do the erase all content and settings a second time and this time choose to restore from your original backup.
First of all, check usage in the iPad settings app and see what's eating your space.
Videos are huge. Delete a couple of minutes and you open up quite a bit. Don't forget the messages kind of apps, if you send/receive many photos, Emojies, vids, etc, in these sort of apps they grow pretty large. Delete a couple of conversations.
Then: connecting with a Lightning cable is hugely faster than Bluetooth. When you open iTunes with the iPad connected it will tell you there's an upgrade and tell you what to do. Upgrading through iTunes will also need less space than over the air (OTA). At least it did with 8.0.