it's actually perfectly okay. I did the same thing that lord of the rings said and it worked. but if you still can't figure it out. i'll give you step by step instructions:

1.) Download your theme
2.) Go to your file options. If you don't know how to get there you can just click help and support and type in hidden.
3.) Then click the show hidden files.
4.) Click the go to folder options link
5.) Click the View tab in folder options
6.) Under the hidden files and folders, click show hidden files.
7.) Right under that unclick hide extensions for known file types
8.) Under that unclick hide protected operating system files
9.) Go to your My Computer icon and click it
10.) Click your local disk drive (C
11.) If you have Vista click the users options, If you have XP click the documents and settings.
12.) Click yourself
13.) Click Applications and Data
14.) Click Limewire
15.) Click Themes
16.) Unzip your theme and put the folder in the themes folder
17.) After you do that, go pack to the .zip file (not the folder you just made, the actual .zip file) and rename it to yourtheme.lwtp, instead of yourtheme.zip
18.) After that it should say that this will make the file not work but still click okay because it does work.
19.) Now put your newly made .lwpt file into your themes folder
20.) Load Limewire
21.) Click View
22.) Click your theme
23.) Click refresh skins and that should do it. If it doesn't show up just click your theme again and it should work.

And your all set.