Q. How to check that : "IP is at the idle stop position"
 

I've got a seperate thread open to try to resolve a no start problem that I I caused when I changed the fuel filters and the glow plugs. The car had been running before my wrenching. I'm also reading threads to hope that there is an answer in one of them.

I read , Check that the IP is at the idle stop position.

How would I do that?

Not the best ideal to start an additional thread it just confuses things. I would not leave the areas you worked in yet. You have disturbed something in my opinion.
Slow down,stop and think about it. Simple checks like if your glow plugs are now coming on since you changed them seem more appropiate.