Less worried about old shoe parts (5)
I believe the answer is:
soles
'shoe parts' is the definition.
(I've seen this in another clue)
'less worried about old' is the wordplay.
'worried' indicates anagramming the letters.
'about' indicates putting letters inside.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'less' with letters rearranged gives 'sles'.
'sles' placed around 'o' is 'SOLES'.
(Other definitions for soles that I've seen before include "Shoe bottoms" , "Undersides of feet" , "They're always under one's feet!" , "Undersurfaces of feet" , "Fish; bottoms of feet" .)