Can't edit / delete .htaccess - how to change base dir?

I've read a thread about cpanel creating an .htaccess that can't be edited or deleted, but this doesn't seem to be the case here. Here's my .htaccess:

RewriteEngine On
RewriteBase /reports/

#uploaded files
RewriteRule ^(.*/)?files/$ index.php [L]
RewriteCond %{REQUEST_URI} !.*wp-content/plugins.*
RewriteRule ^(.*/)?files/(.*) wp-content/blogs.php?file=$2 [L]

# add a trailing slash to /wp-admin
RewriteCond %{REQUEST_URI} ^.*/wp-admin$
RewriteRule ^(.+)$ $1/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule . - [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-.*) $2 [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(.*\.php)$ $2 [L]
RewriteRule . index.php [L]

<IfModule mod_security.c>
<Files async-upload.php>
SecFilterEngine Off
SecFilterScanPOST Off
</Files>

I can't change permissions and even tried directly from cPanel too.

I want to change the base dir to / and then have a different page about blogs at /reports/ and mu is installed in /reports/,

I have several WP blog installations on my server and never had problem editing the .htaccess. Any clues?