There are perforations along the inner and outer edges of the adhesive strip.

Carefully tear along the perforations to separate the outer portion of the adhesive backing from the adhesive strip.

Carefully tear along the inner perforations to separate the inner portion of the blue backing from the adhesive strip.

Be very careful not to tear the adhesive, the white backing, or the blue backing underneath the adhesive. Only remove the blue plastic surrounding the adhesive strip.

When you're done, you should have just have a phone-shaped ring of adhesive with blue backing on one side and white backing on the other.