To download a skin, simply click on the skin name or the sample screenshot. Be sure to download the BMP file, not the GIF screenshot. You can then apply the newly downloaded skin by right-clicking on the PowerArchiver toolbar and selecting 'Skin PowerArchiver Toolbar'. For Full PowerArchiver Skins click here.
The second skin inspired by Go!Zilla: this includes text labels in the style of the original program.
You should disable the "show labels" option to enjoy it best. Try and see how many more buttons you can view on your toolbar with this skin.