Matching a question mark in .htaccess - .htaccess

Question

I'm trying to set up some 301 redirects for old Kayako helpdesk URL's. The old URL's were;
example.com/index.php?/rest_of_url
I've set up rewriting so the URL's are prettier example.com/rest_of_url, and I'm trying to 301 redirect all old URL's to new. I've tried the following but they don't appear to work;
RewriteRule ^index.php?/(.*)?$ /$1 [R=301,L]
RewriteRule ^index.php\?/(.*)?$ /$1 [R=301,L]
RewriteRule ^index.(.*)/(.*)?$ /$2 [R=301,L]
I can't quite figure it out.
EDIT:
Here is the whole .htaccess file
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule .* https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
RewriteCond %{QUERY_STRING} ^/(.*)$
RewriteRule ^index\.php$ /%1? [R=302,L]
RewriteCond $1 !^(admin|api|console|favicon\.ico|robots\.txt|sitemap\.xml|index\.php|tiny_mce_gzip\.php|cron|onsite|staff|rss|setup|visitor|winapp|wallboard|__swift) [NC]
RewriteCond $1 !\.(jpg|jpeg|png|gif|js|css|htm|html)$ [NC]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)$ index.php?/$1 [L]
RewriteCond $1 !^(favicon\.ico|robots\.txt|sitemap\.xml|index\.php|tiny_mce_gzip\.php|__swift) [NC]
RewriteCond $1 !\.(jpg|jpeg|png|gif|js|css|htm|html)$ [NC]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^([a-zA-Z0-9]*)/(.*)$ $1/index.php?/$2 [L]
</IfModule>

Answer 1

The part after the question mark is not in the RewriteRule url.
You have to use %{QUERY_STRING}:
RewriteCond %{QUERY_STRING} ^/(.*)$
RewriteRule ^index\.php$ /%1? [R=301,L]
%1is the first (.*) in the last RewriteCond.
In your case, without loop, use:
RewriteCond %{THE_REQUEST} \s/+index\.php\?([^\s&]+) [NC]
RewriteRule ^ /%1? [R=302,L,NE]