help on themes please

[goliath6900]

i'm new to iphone and just did the jailbreak and unlock. i downloaded a theme under theme(complete) in cydia. winterboard is already on settings. i selected the theme that i downloaded but nothing happens. also the i tried the White Icons Labels, samethin. nothing happens. i did not press the Optimize Themes yet. If i press it, how do i revert to the stock theme since the png image will be replaced? thanks.

nevermind. figured it out.