Step 1: Find a skin you would like to use. Once you find a skin you desire download and move the folder onto your desktop. After moving your skin open your Skin Installer Ultimate client, On the ==Add New Skin== tab click the button add Files then find the folder you download, select it and hit open.
Step 2: Once you have added the files click the button "Add to DataBase" It's going to ask you to name the skin this can be anything you choose "Hit Okay/Yes for anything that pops up". After this should move you to the ==Install Existing Skin== Tab where you skin will be displayed. Click the checkbox next to the skin icon.
Step 3: Click install, it's going to ask you about Install Preferences don't change anything just hit save. After setting up your Install Preferences it's going to ask what model do you want to replace, always check Default then click done.
Now your Custom skin is ready to go and should appear in your next game enjoy.