how do l remove my ipad from my account?

Begin by disabling Find My iPad:

Settings > [Your Name / AppleID] > Find My > Find My iPad > Find My iPad - set to OFF

Next, sign-out from the App Store:

Settings > [Your Name / AppleID] > Media & Purchases > Sign Out

Finally, sign-out from your AppleID:

Settings > [Your Name / AppleID] > Sign Out

Your device will now be fully removed from your AppleID account.

If you are actually preparing your iPad to sell, trade-in or give to a new owner, you should follow this process to properly prepare the iPad:

What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch - Apple Support

Are you referring to removing your iPad from your iCloud Account. If so go in to setting’s at the top click on your name then click on the device you want to remove and at the bottom it should say remove device click on that, as I am not testing you might need to enter you Apple ID password.