I don't know me and a lad from REME got given a rapier system to fix.
It took the two of us 30 mins to set up with him directing, an hour to fix the thing, then 30 mins "testing" it pointing it at passing aircraft. It didn't have bang loaded but I reckon both of us would have hit things.
Tanks etc don't even have keys to start them. The weapon systems have interlocks to stop you killing yourself but if all of them are in and you press or pull the tit it will fire.
All you one need is one person that is a No 1(commander) or technician for the weapon system and you can use it.
Hell at 17 years old I was firing light guns and FH70 as the gunners were a man shy of a gun crew to drive the wagon and someone thought it was funny to put me on the sights.
Maintaining them and keeping them working is a bit of a pig but the actual deploying and firing of a working system is easy. Hell if it was difficult they wouldn't give them to the gunners, they would give them to the sappers or REME.