Linking prims - but restricting script action to one prim

I am building an item with a lid. I want to put an opening/closing script in the lid prim, but when I link it all together.....the whole thing moves. How can I keep the items linked but restrict the action to the lid. I've tried linking in different order so the prim with the script is not the root....but that doesn't help.

I'm very inexperienced in scripting and building and I'm using a ready made script for the opening and closing....so please keep it as simple as you can...sorry.

If the lid is one prim it should be simple.
1.Place the script in the lid.
2.Link it all so that the lid is not the root prim; i.e in the order of selection the lid must NOT be the last prim selected

It's three prims....one for the lid....one for the axle (because otherwise the lid rotates at the centre...not the edge/hinge and one for the base box....

I've linked them all....and as soon as I add the base prim....the whole item rotates....

Then you asked for it
Try to make the lid one prim by cutting the prim in half, then it will still turn around the center but it appears to be around the edge. Get rid of the axle prim.

Thank you so much, Dora....a simple solution, but this had been bugging me. I've cracked it now and it's all thanks to you!!

Thanks for all your help.