Wooden window frame - how to ?

[Phill.poulter@gmail.]

Hi all, I'm looking to replace the bottom section of this wooden window frame illustrated iView attachment 350574n the pic. It would guess that that each section of 4 panes has been fitted within the larger frame. I want to remove the left hand section of 4 panes for ease of repair. The question is, does anyone know if there is a standard way off attaching the 4 frame pane to the larger pane; a screw at the centre of each surround perhaps ? glue ? Either or both of these may be true or another method ? The question I'm looking to have answered please is, is there a classic, standard way of attaching the 4 frame pane ? Many thanks.