Tries to transform observances (5)
I believe the answer is:
rites
'observances' is the definition.
(I have seen 'Religious observances' mean 'rites' so perhaps 'observances' could also mean 'rites')
'tries to transform' is the wordplay.
'to transform' is an anagram indicator.
'tries' with letters rearranged gives 'RITES'.
(Other definitions for rites that I've seen before include "formal procedure" , "Formal ceremonial procedures" , "Ceremonial forms" , "Rituals" , "Ceremonial observances" .)