Q: How do I change the id on iTunes to match the id on the ipad

Hello there, Bobbaileyfl.

It sounds like you're trying to sign into iTunes on your iPad with a different Apple ID. The following Knowledge Base article offers up some great instruction on how to do just that:

Sign in with a different Apple ID on your iPhone, iPad, or iPod touch - Apple Support

iTunes, iBooks, and App Store

 

1. Tap Settings > iTunes & App Store.
2. Tap your Apple ID. If you see the option to Sign In, you can change your Apple ID now.
   
3. Tap Sign Out.
4. Go to Settings > iTunes & App Store.
5. Enter your Apple ID and password, then tap Sign In.
   

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Cheers.