Uninstall this version. Then download and install the US version from http://en-us.www.mozilla.com/en-US/. Seems simple enough.
I'm in Israel with my laptop, am connected to internet via the apartment I'm in, was having problems with internet and installed Mozilla Firefox which has installed all the information in Hebrew - and I don't understand that language enough to operate on internet. I can't get in touch with Firefox or Google to make the change to English. Has anyone a solution for this problem...is there one?