Blow up having made tiny changes (8)
I believe the answer is:
dynamite
'blow up' is the definition.
(dynamiting is a kind of blowing up)
'made tiny changes' is the wordplay.
'changes' indicates an anagram.
'made'+'tiny'='madetiny'
'madetiny' is an anagram of 'DYNAMITE'.
'having' acts as a link.
(Other definitions for dynamite that I've seen before include "Fantastic" , "Explosive - amazing thing" , "dangerous stuff" , "Spectacular (or dangerous) person (or thing)" , "Nobel's invention" .)