Tool to cut the cabinet out without damaging ceiling

[Peterpiper]

Hello everyonei hope you're all keeping cool.

I've taken out this chimney and want to remove the top and bottom of this cabinet and replace it with a full top and bottom. Its painted ply and I have no idea as to how to remove it without damage to the the ceiling. Any ideas?

Also this in on the first floor bedroom - I'm taken the bricks out to the same level as the joists and won't be removing the chimney below it on the ground floor. Do I need to allow air to pass between below floor boards on first floor and the ground floor chimney or could I lay DPC and completely seal the chimney hole between first floor ground and ground floor top of chimney breast?

Many thanks in advance

 

[Tigercubrider]

not a brilliant photo but the simplest is to use a hand saw in the centre of the cabinet, upside down, and cut nearly all the way through the top bar, then ditto at the bottom bar. The sides might also be screwed in but once the cabinet in in two halves, it will be easy.
A multi tool or jigsaw (check blade length ) might do but a hand saw is easiest

 

[Deleted member 174758]

This is a job for a multitool - it's slow, but you run the least risk of damage to the ceiling and operator injury (choosing from jigsaw, recip saw, hand saw, circular saw and multitool). For speed a recip saw is probably the best, but it comes with additional risk of damage

 

[Peterpiper]

Thank you so much! Much obliged