Converting one way switch to two way + outside light

[gronny]

This is my first ever post so go easy on me please if this is a bit sketchy.

My existing lighting is a one gang one way switch to loop-in rose (i.e. 8 terminals in the lighting rose)

I want to add a 2 gang switch at the opposite end of the kitchen (2 way with the existing light switch with the 2nd switch for a one way outside light).

I understand that I need to feed a new 3 core and earth between the two switches but I am now finding it difficult to work out how to configure the whole lot together (when I plan it on paper it starts to look well, confusing?)

Can anyone provide me with a model/sample diagram or any advise/guidance?

 

[ban-all-sheds]

//www.diynot.com/wiki/electrics:two-way-lighting

Also you won't be able to make the outside light work from just the switch, as you'll not have a neutral present - you'll need to put a 4-terminal JB somewhere convenient, take the circuit loop cable to it, and the light cable, and a drop cable to the new switch, or take a neutral to the existing 1G1W switch (e.g. by replacing the drop cable with 3C+E) and from there to the new switch (e.g. by using 2 x twin & earth instead of the 3C+E link).

Are you aware that adding light switches in a kitchen is notifiable?