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"Removing a Website from WordPress: A Step-by-Step Guide to Deleting Your Site"
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Let’s say you have built a WordPress site,
And you want to go back to the default WordPress site.
You can do that easily by following these steps.

Step 1 : Install the WP Reset plugin.

Step 2 : Reset your WordPress site using the plugin.
Before you reset your website, it is good to have a backup of your site.
Now If you want to quickly revert to your current site, after the reset,
You can also take a snapshot of your site
Go to your dashboard ► Tools ► WP Reset ► Snapshots and click “Create Snapshot”.
Once you've created, you can reset your site.
To reset, go to the reset tab on WP reset plugin and click “Reset WordPress”.
As soon as you click reset WordPress, your site will be back to its default state.

Now, if you want to quickly revert back to your previous site, you can restore the snapshot.
To restore the snapshot, go to Dashboard ► WP Reset ► Snapshots
Now click ‘Actions’ on the snapshot you created and click ‘Restore Snapshot’.