Remove the category from wordpress urls permalink /%category%/%postname% without a plugin

To remove the annoying:
example.com/category/%category%/%postname%

and get the better:
example.com/%category%/%postname%

I added this line before the wordpress standard .htaccess code:

Options +FollowSymlinks
this is the old .htaccess contents:

<IfModulemod_rewrite.c>
RewriteEngine On 
RewriteBase / 
RewriteRule ^index\.php$ - [L] 
RewriteCond %{REQUEST_FILENAME} !-f 
RewriteCond %{REQUEST_FILENAME} !-d 
RewriteRule . /index.php [L] 
</IfModule>

this is the new one

Options +FollowSymlinks
<IfModulemod_rewrite.c>
RewriteEngine On 
RewriteBase / 
RewriteRule ^index\.php$ - [L] 
RewriteCond %{REQUEST_FILENAME} !-f 
RewriteCond %{REQUEST_FILENAME} !-d 
RewriteRule . /index.php [L] 
</IfModule>