Spoil appearance of part of the cafe, disabled needing a lift (6)
'spoil appearance of' is the definition.
'part of the cafe disabled needing a lift' is the wordplay.
'part of' indicates a hidden word.
'needing a lift' is a reversal indicator (in a down clue, letters go up).
'ecafed' is hidden in the letters of 'the cafe disabled'.
'ecafed' written backwards gives 'DEFACE'.
(Other definitions for deface that I've seen before include "blemish", "Mar or spoil the appearance of", "Wantonly spoil the look of", "ruin", "Spoil surface of, mar".)