This is Zipp®'s new stealthy color scheme. Each decal kit has seven large and a full assortment of valve-hole decals sufficient to cover one wheel.
If your decals are adhesive and not molded in, you can use a hair dryer to soften the glue, grab a corner and gently pull off, scrape the remainder off with your nails or a blunt popsicle stick, clean well with acetone or white spirits, allow to evaporate and apply the new decals.
If the original decals are molded in, (use the thumbnail test to feel for an edge) you will have to purchase a set of decals and apply them over the top. Molded in decals cannot be removed without structural damage to the rim.
Peel or gently scrap off all parts of the old decal. Clean the rim well with soap and water and then use rubbing alcohol or acetone to remove any residual grime and grease. Slowly peel the backing off the decal, position the new decal over the rim and apply staring at one end. Work the air bubbles from the center toward the outside. Use a squeegee applicator (PA-1 from 3M™) to work the decal into the dimples.
Start 1/4 inch from the spoke bed. Please the first decal centered and oposite the valve hole. The center of the two remaining decals on that side will be 120 degrees from the first. The valve hole decal is placed in the center of the rim directly below the valve hole. No part of the decal should cover the brake tracks.
Please watch the video on replacing decals of the Video FAQ of Zipp.com.