The gear cables are attached to the top of the gearbox on a cradle held in place by 3 x 10mm bolts. It’s far easier to unbolt this cradle and remove the cables from the car attached to this.
As the cables go through the bulkhead, they are held in place by 2 pieces of c shaped black plastic that clip together at the centre. This needs to be removed in order to release the cables and allow them to be pulled through from the engine bay side.
No photos sorry, but if you follow the cables back to the bulkhead you can’t miss them when feeling by hand.