1.Log in to your blogger dashboard
2.Go to --> layout- -> Edit HTML
3.Scroll down to where you see this:
]]></b:skin>
4.Now add below code just before ]]></b:skin> tag .
#navbar-iframe{opacity:0.0;filter:alpha(Opacity=0)}
#navbar-iframe:hover{opacity:1.0;filter:alpha(Opacity=100, FinishedOpacity=100)}
Look at the example below.
#navbar-iframe{opacity:0.0;filter:alpha(Opacity=0)}
#navbar-iframe:hover{opacity:1.0;filter:alpha(Opacity=100, FinishedOpacity=100)}
]]></b:skin>
5.Click on "Save Templates" and now you are done.