Thread:Project:Support desk/i want to change the layout of mediawiki.(look and feel)

hi, i have latest version of mediawiki and i m trying to change footer(powered by mediawiki) url by skin.php file but nothing is reflecting to me.so pls provide me useful suggestions, how can i change the layout of the page.

i also want to change the location of search bar and button texts and size, suggest me from where i can do all these changes easily.