If it wasn't so worrying it would be hilarious.
The MoD say there was no danger as the missile parts were packed in boxes
OH! Why didn't you say so! That makes everything alright then!
The stowaway probably knew that that during ground defence training all HM Forces have to watch a frustrating video called 'Intruders On Military Property: Their Rights and How You Must Never Speak To Them In A Nasty Tone Of Voice, Let Alone Point A Weapon At Them'