How do u reinstall Google after I accidentally uninstall it

Isobel, Check the attached links,instruction and guides, Good luck
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Reinstall and re enable apps
How to Recover Deleted Apps on Android Phone or Tablet
How to Restore Google Play Store if You Accidentally Remove It

Check out this link, it may help...
ve deleted Google Play Store How can reinstall it

Wipe the play stores cache. Go to settings, apps, all, Google play store, and clear cache.

If that doesn't work than uninstall and reinstall the play store.

When you uninstall updates to Google Play Store you are actually uninstalling updates to the Google Play Store app itself and not your other installed applications and their settings what you're actually doing is downgrading the Google Play app itself to the version that came shipped on your nook HD Plus. I know this Uninstall Updates wording tends to freak a lot of folks out because they think it means all updates to everything. In the app itself sometimes this is necessary if a bug is introduced into the most recent version of the Google Play app. Don't worry over time the Google Play app itself will automatically update itself again. If newer versions still have a bug on your system just uninstall updates again until they get it fixed. Over the last two and a half weeks a minor bug was discovered in Google Play that the very second you entered an apps description page Google Play would immediately stop responding to the system and crash. I sent a blind email to a Google support email address I hoped could forward it to the Google Play staff. I sent the email in about this problem about a week ago. It least on my Nook HD plus for the past two and a half days this problem seem to have corrected itself. Knock on wood.

You are the second question in a week about this very same problem between the Google Play Store app and Nooks. Hope this answers both questions and provides a solid workaround should Google Play Store ever get buggy again in the future.

Try to uninstall updates of play store.. Settings>apps>Google play store>uninstall updates..

search "google play download free" on google. before you download, make sure you enable installations from unknown sorces in settings

Uninstall the app then reinstalling otherwise contact your ISP

Should be as easy as going to google play and downloading and installing the app, then entering your username and password, that is if you are running an Android based device. Otherwise you'd need to access whichever store you buy books/apps from and reinstall it from there.