The letters in first half and second half of word are written in reverse order and in group of letters so obtained, each letter in first half is moved one step forward while that in second half is moved one step backward, to get code.
Thus, we have :
STABILISED => STABI/LISED => IBATS/DESIL => JCBUT/CDRHK

Divide word into six sets of two letters each and label se sets from 1 to 6. Then, code contains se sets in order 4, 3, 5, 2, 6, 1 with letters of sets 3, 2, 1 written in a reverse order.
Thus, we have :
VI SH WA NA TH AN => NA AW TH HS AN IV.

Each of first four letters in word is moved one step backward, while each of last five letters is moved one step forward to obtain corresponding letter of code.

The first letter of word is moved one step forward to obtain first letter of code, while or letters remain unaltered.

The first, second, third, fourth, . . . . . letters of word are moved one, two, three, four, . . . . . steps backward respectively to obtain corresponding letters of code.

D is used for F.
G is used for I.
P is used for R.
and
C is used for E. Thus, it is clear that each letter of word FIRE stands for each corresponding letter of coded word DGPC two places ahead. By applying same principle, letters QFMR will stand for SHOT. Hence, last letter of coded word is R.

Each letter in word, except middle letter, is moved one step backward while middle letter is moved one step forward to obtain corresponding letter of code.

The code contains letters of word in order - third, fourth, second, fifth, first and sixth.

Each letter in word is moved three steps forward to obtain corresponding letter of code.

We sleep at Night and Night is called Sunshine. So, we sleep in Sunshine.