Our kitchen has 9 x downlighters that where installed at the same time and are all switched from a single wall switch which is mounting in a mdf cooking range surround (so plenty of space behind the switch).
I’d like to change the way the lights are switched so that 4 are on one switch and the other 5 are on a separate switch [in a double gang].
Is this likely to be a reasonably simple job or is it likely to be tricky unless the floorboards are lifted in the room above?

Remove the 2 screws on the front of the switch and have look at how many cables are in there. Only one and all the lights are linked together, so they will need rewiring. Educated guess will be that only one switch wire has been taken from the switch.

And then it depends if they are all linked together or going through junction boxes

If they are linked together then it should be possible with fishing rods to split them in 2 circuits and then fish wires down to switch.

When your house was wird up will have a fair effect on this though, if its all old school through junction boxes in the roof itll be much easier with the floor up

You been drinking Trail Rat ?

Do you know how the lights are wired in at the moment? Are they fed from a junction box? They will most likely be daisy chained after the first one – so you could disconnect the T&E after the fourth or fifth one, this would allow the first four to be operated via the original switch. You would then need to run a new live to the switch (to connect to the 2nd gang) and then the switched live from the switch back to the T&E you previously disconnected. You would obviously have to have a neutral and earth at the jct box. Its easy provided you can find the perm live into the kitchen lights. Stick a junction box in that, from there do the above.

By fishing rods I’d think t_r means rods ( as in anything from cable trunking covers to bamboo cains) for pulling cable rather than something you may use for catching carp or North Atlantic sea trout or whatever.

Lights were put in 11 years ago. I’ll stick a camera into the roof space tomorrow and see what’s what.
Not planning on doing it myself, just wondering roughly how much it would cost me to get it done.

If you lived next door I’d do it for £120

If there is a roof space above that is easily accessible, it should be pretty easy to do, half a days work tops and a new bit of T&E and possibly a new junction box. Get back with the laughable prices you get!