Download Canon EOS Rebel T1i Eyepiece Replacement – If the eyepiece, the rubber or plastic rectangular piece around the viewfinder, is loose, broken, or lost, then you should read this guide to replace it. This guide will provide you with intructions to take out the existing broken eyepiece and replace with a new one.
Step 1 — Eyepiece If necessary, remove the rubber grip around the eyepiece by gently peeling it off. Use your index finger and thumb to grip the eyepiece by the sides.
Step 2 Pinch your fingers together and wiggle the eye piece gently upwards until it is detached from the camera.