Moves over and treads on assistant carrying son (5,5)

I believe the answer is:

steps aside

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'moves over' is the definition.
(to step aside is to move over)

'treads on assistant carrying son' is the wordplay.
'treads' becomes 'steps' ('step' can be a synonym of 'tread').
'on assistant' becomes 'aide' (aide is a kind of assistant. I am not sure about the 'on' bit.).
'carrying' indicates putting letters inside.
'son' becomes 's' (genealogical abbreviation for son).
'aide' enclosing 's' is 'aside'.
'steps'+'aside'='STEPS ASIDE'

'and' is the link.

Can you help me to learn more?

(Another definition for steps aside that I've seen is " Leaves".)

I've seen this clue in The Telegraph.

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