The tricky bit is the removal of the glass which has a probability of breaking increasing in the winter months according to my dealer, when they corrected a build issue with heated wing mirror leads not clipped in when it left the factory. They broke mine and substituted for a non blind spot mirror. I turned down the chance of taking the one they fitted out when the blind spot one came in. Got them to do it rather than breaking it.
The Ateca General body repairs, exterior - Edition 11.2016, pages 376 - 378 covers the procedure.
– Remove the wing mirror glass ⇒ page 375 .
– Undo the clips -arrows A- and pull the housing -1- in the di‐
rection of the -arrows B- at the same time.
– With the lever - 3409- , release the clips on the housing -1- at
the points indicated by the -arrow A-.
– Move the housing -1- it in the direction of -arrow B- and re‐
Fit in reverse order from removal, remembering the following:
A Leon YouTube video shows brute force without removing the mirror and doing the clips... hmmm. What did you do ?. Suspect the brute force method isn't the one to use, may be a variation from the Ateca to Leon procedure. Ateca method attached just in case anyone thinks of following the Leon YouTube video.