Another K12 timing chain question!

[Micra2]

So, I have a 1.2 petrol micra of 2003 vintage. One of the kids had it as a first car, but has now upgraded (just in time). The last week got very bad, non starting etc. Prefer to sell the car on as a runner, so changing the chain. I've read a few threads on the chains, but I have read opposing views on the vvt. In short, I intend to change the chain, retaining the current vvt. I can rotate the 3 sprockets to align points (current chain still on so will put crank at 12 o'clock, outlet at 12 o'clock and inlet at 11 oclock), but does the vvt need to have air to unlock a pin or not? If so, is it activated before sliding the chain on? Probably obvious once the job has been done once, but conflicting opinions make this tricky. It's been stripped out ready for the old chain to come off). Any advise please?