Overhaul locomotives leaving one half of platform (9)
I believe the answer is:
transform
'overhaul' is the definition.
The definition and answer can be both related to change as well as being verbs in their base form.
Maybe they are linked in a way I don't understand?
'locomotives leaving one half of platform' is the wordplay.
'locomotives leaving' becomes 'trans' (I am not sure about this - if you are sure you should believe this answer much more).
'one half of' indicates taking half.
'platform' halved is 'form'.
'trans'+'form'='TRANSFORM'
Can you help me to learn more?
(Other definitions for transform that I've seen before include "adapt" , "Change the voltage I" , "Change markedly" , "Subject to change" , "Make great change in appearance of" .)