Hello,
In regards to the permissions change, you can typically accomplish this using a ftp program. An example of one would be file-zilla. A great article describing file permission modification along with a tutorial about permission changes with file-zilla can be found here
There are a few other things that you should also look into. One of which, is ensuring that your wordpress upload directory is set correctly. You can find this setting under “Settings” > “Miscellaneous” on your wordpress blog admin panel, by default it should be set to ‘wp-content/uploads‘.
WordPress generally looks for images within the uploads directory so if your uploads directory is set elsewhere, then your images and files will may not display correctly. It is possible however, to set it to another directory.
Also make sure that file uploads is enabled for your blog. If you have access to your php.ini file, you can check to see if file uploads is enabled and that the proper upload temp directory is set for your site.
The two settings to look for would be:
file_uploads = On (make sure this is set to on)
upload_tmp_dir = (this should be set to whatever your tmp directory is on the server)
If you do not have access to these settings, your hosting company should be able to assist you so contact them. Hope this information is helpful.
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