okay basically
you unzip the files in the zipped folder (which is the purple skins folder and lwtp file), into this directory;

C Drive: >Documents and settings: > (your name): > Application Data: > Limewire: > themes.

Open Limewire and click 'View', 'Apply skins', then refresh skins
Then, 'View', 'Apply skins', and select the skin.

P.S Bare in mind that 'Application Data' is a Hidden Folder.
Hope this helps