P38A Probably more stupid questions.

4 litre petrol 1998 gems engine.
What is the correct size socket for the exhaust manifold.I know they are splined and last time bumbled along with mixtures of metric and imperial. So much so that one of them has crossthreaded and won't seal the manifold. I just want to buy the one socket as opposed to buying a set.
Having aquired a replacement head is it possible to remove and replace the offside cylinder head without a complete strip down and if so what are the pitfalls.
Sorry for all these questions haven't owned a car since 2001 and only got this because the wife lost her motability car. How someone who is terminally ill doesn't need the higher benefits and car is beyond me. But that is another story.
Hope someone can let me know the socket size so I can add it to my expanding tool kit p38 style. I'm gonna need a bigger shed.

12 point splined. Can't remember the exact size. 13 or 15 I think. I hate off and near as it really confuses me. So the driver's side(UK) head is considerably trickier than the passenger side head because of the need to remove the steering intermediate column to access the manifold bolts at the back. All your intake gubbins needs to come off anyway. A tricky thing is to remove the rockers covers though as these take a small spline socket with an odd thin wall. My advice is to saw a slot in them so you can tighten with a screwdriver! When you remove the push rods keep in order and don't let them stick to the rockers, be lifted a bit then fall off into the valley. Otherwise it's sump off or magnet job.

Cheers already done the cut a slot in the buggers last time I had them off. Once bitten...........

Near - NEAR TO THE KERB