Upvc window won't close.

[zoothorn]

Hi chaps,

 

One of my old folks' newish upvc windows (the only one opening forwards, at the bottom) won't close. I can see the metal mech on the underside of window, clashes with the frame's metal recess sections (pic 2: pink arrows show A to B clash).
 

So effectively, the window just needs to be 'shoved up a bit' just say 5mm to gain the clearance again IMO. Worked fine before, but, I did notice it was always tight fit to close this window.
 

Any idea if this is a job one can do, as opposed to getting a pro in? Looked on YouTube but can't see the exact fwd btm opening similar type window.

 

Pics added. Thanks for any help, Zoothorn
 

Edited July 16 by zoothorn