Model again needing break, see, when upset (7)
I believe the answer is:
restyle
'model again' is the definition.
(style or model again)
'break see when upset' is the wordplay.
'break' becomes 'rest' (a rest is taking a break).
'see' becomes 'ely' (see is a place with a cathedral - e.g. Ely).
'when upset' says the letters should be written backwards (in a down clue - set, written, up).
'ely' in reverse letter order is 'yle'.
'rest'+'yle'='RESTYLE'
'needing' acts as a link.
(Other definitions for restyle that I've seen before include "Design afresh" , "Remake in a new form" , "Create a new image" , "Of hair, shape in different fashion" , "Give a makeover to" .)