This is for firefox
1.Type about:config into Firefox’s address bar and press Enter. You’ll see a warning – be careful when you change settings here, you could mess up Firefox’s settings.
2.Type useragent into the filter box. We’re looking for the general.useragent.override preference, but it probably won’t exist on your system.
3.To create the preference, right-click on the about:config page, point to New, and select String.
4.Name the preference general.useragent.override
5.Enter your desired user agent as the value of the preference. You’ll have to look up your desired user agent on the web and enter it exactly. For example, the following user agent is used by Opera mini for android: Opera/9.80 (Android; Opera Mini/7.6.35766/35.5706; U; en) Presto/2.8.119 Version/11.10
This setting persists until you change it – even if you close and reopen Firefox. To revert Firefox to the default user agent, right-click the general.useragent.override preference and select Reset.
You can also change the free download manager user agent if you want to be downloading
1.go to options
3.select new download
4.select advanced that is in front of "set download folder"
5.select the tab named protocol
6.in the text box in front of "identify on server as" paste this string: Opera/9.80 (Android; Opera Mini/7.6.35766/35.5706; U; en) Presto/2.8.119 Version/11.10
7.paste the same string to the text box in front of referrer
Now you can browse and download with the opera mini bundles