Instructions
Double-click a shortcut for the IMVU client, a standalone program that accesses the Internet to interact with others.
Enter your log-in information and click "Login" on the dialogue box that appears.
Select the "Shop" option from the home page of your character portal. "Shop" is the second button of the five available commands.
Expand the "Rooms" category of items and browse through them for a floor you like. Click "Buy" under the floor you want.
Return to the home page and press the "My Room" command, then press the hammer icon in the upper-left corner of the screen and drag the floor pattern over your own floor from your inventory along the bottom.