Fatal Error!!

Hi Everybody!
Thanks to this fatal error I cannot access the admin page of my blog anymore:

Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 311296 bytes) in /web/htdocs/www.@@@@@@.@@/home/parrocchia/wp-content/plugins/nextgen-gallery/products/photocrati_nextgen/modules/ngglegacy/admin/manage-images.php on line 499

I cannot increase the memory size on php.ini since I am on a shared service.
What can I do to get it running again?

Thanks in advance