Fix and clean, with difficulty, the spire (8)
I believe the answer is:
pinnacle
'the spire' is the definition.
(pinnacle is a kind of spire)
'fix and clean with difficulty' is the wordplay.
'fix' becomes 'pin' (pinning is a kind of fixing).
'and' says to put letters next to each other.
'with difficulty' indicates an anagram.
'clean' is an anagram of 'nacle'.
'pin'+'nacle'='PINNACLE'
(Other definitions for pinnacle that I've seen before include "Acme" , "The highest point, say of fame" , "Crown" , "Apex" , "Highest point (of fame or building)" .)