Lots keen to change basic scheme (8)
I believe the answer is:
'basic scheme' is the definition.
(I've seen this before)
'lots keen to change' is the wordplay.
'to change' is an anagram indicator.
'lotskeen' is an anagram of 'SKELETON'.
(Other definitions for skeleton that I've seen before include "Type of key", "Bony frame", "Scheme reduced to its essential elements", "set of bones?", "This key fits many locks".)