Answer:

RETROFIT

AnswerCrossword Clue
RETROFITSubstitute new parts for old
RETROFITUpgrade, in a way
RETROFITModernize mechanically
RETROFITModify equipment, in a way
RETROFITModernize, in a way
RETROFITModernize, maybe
RETROFITFurnish a plane with new parts
RETROFITModernize, as an airplane
RETROFITPut new parts on, in a way
RETROFITAdd new parts to, say
RETROFITSupply with updated parts