The article doesn’t say...did they take out the Renault engine and put in a good one?
How long does it take to change a couple rubber bands? lol
It was likely part of a training exercise. The Maintenance team brought it on board with them to perform this as a training exercise. Our guys (or theirs) would also fuel them, and practice arming them. Routine stuff.
In a real shooting war they might need these jets to be able to land and be serviced on our flat tops.