Full-frame in acetate or plastic:
To remove the original lenses, identify the most flexible or straight section of the frame to start from. Firmly press on the inside of the lens (the concave side) to pop it out. In some cases, gently warming the frame can make the plastic more pliable and facilitate removal. A good method is to grip the frame securely and push it away from the lens.
To insert the new lenses, follow the reverse process: start from the more curved side (usually near the temple) and carefully work along the edge of the frame, finishing the insertion on the nose side. With the right amount of pressure, the lens will snap into place.
Fully metal frame:
These frames usually have a small screw on the back near the temples. To install new lenses, slightly loosen this screw without removing it completely — this will widen the frame and make lens placement easier. Carefully align the replacement lenses, then retighten the screw to secure them.
Semi-rimless frame:
To remove the lenses, gently grasp them and push towards the temple side, then lift slightly to release.
To insert the new lenses, begin by placing the thinnest part of the lens (usually on the temple side) into the frame, then slide the rest of the lens upward from the bottom to complete the installation.
