Lots keen to change basic scheme (8)
I believe the answer is:
skeleton
'basic scheme' is the definition.
(I've seen this before)
'lots keen to change' is the wordplay.
'to change' is an anagram indicator.
'lots'+'keen'='lotskeen'
'lotskeen' is an anagram of 'SKELETON'.
(Other definitions for skeleton that I've seen before include "Internal structure of the body" , "Framework of the body" , "Bone formation in the family cupboard" , "Frame - secret scandal" , "person in no danger of looking fat!" .)