Can I Install the plugin manually ? Yes, you can. Extract the zip file of the "leadsquared-website-topbar.zip" then place the whole folder in the following location "yousite\wp-content\plugins\".
Do I need WordPress newer than 3.0 ? Ans - Yes, your WordPress version should be greater than 3.0
Can I use HTML to tweak the text and effects in the top bar! Ans - Absolutely! For example, if you use My Text, it will help you make your text bold.
How do I uninstall? Go to the Uninstall tab and then click the Uninstall button at the bottom of the page. You'll be sent to the WordPress Plugins page. Now deactivate and uninstall the Plugin
How do I hide the Top Bar? Just go to the configuration page, Click on "Hide", just above the Save button, and then click on Save. The top bar won't be displayed till it is "Shown" again.