Major blunder.. HELP!

I have an active site written with front page but wanted to change over to wp so installed wp in a folder named wp. I am basically thru with the wp site and wanted to be able to access it from the root directory so found instructions found below on how to do so on the wp site. However, I made one mistake and now cant get back into wp-admin to fix it. The instructions below say to open settings/general and change the Site address (URL) to the root directory’s URL which I did but apparently was not paying attention and also changed the WordPress Address (URL) to the root directory. Now am getting this message 500 – Internal server error – There is a problem with the resource you are looking for, and it cannot be displayed. I get this when trying to open the site or wp-admin so am locked out and dont have a clue how to fix this. PLEASE, any help appreciated.

Dave

Using a pre-existing subdirectory install

If you already have WordPress installed in its own folder (e.g., https://example.com/wordpress), then the steps are as follows:
1. Go to the General panel.
2. In the box for Site address (URL): change the address to the root directory’s URL. Example: https://example.com
3. Click Save Changes. (Do not worry about the error message and do not try to see your blog at this point! You will probably get a message about file not found.)
4. Copy (NOT MOVE!) the index.php and .htaccess files from the WordPress (wordpress in our example) directory into the root directory of your site—the latter is probably named something like www or public_html. The .htaccess file is invisible, so you may have to set your FTP client to show hidden files. If you are not using pretty permalinks, then you may not have a .htaccess file. If you are running WordPress on a Windows (IIS) server and are using pretty permalinks, you’ll have a web.config rather than a .htaccess file in your WordPress directory.
5. Edit your root directory’s index.php. 1. Open your root directory’s index.php file in a text editor
2. Change the line that says:
require( dirname( __FILE__ ) . ‘/wp-blog-header.php’ );
to the following, using your directory name for the WordPress core files:
require( dirname( __FILE__ ) . ‘/wordpress/wp-blog-header.php’ );
3. Save the file.

6. Login to your site (if you aren’t still already). The URL should still be https://example.com/wordpress/wp-admin/
7. If you have set up Permalinks, go to the Permalinks panel and update your Permalink structure. WordPress will automatically update your .htaccess file if it has the appropriate file permissions. If WordPress can’t write to your .htaccess file, it will display the new rewrite rules to you, which you should manually copy into your .htaccess file (in the same directory as the main index.php file.)