Many tinys have neckholes that are smaller than the S-hooks, and the hook won't fit through. A hemostat is very helpful for removing the head on these dolls. All you have to do is:
-lift the head very slightly
-with a hemostat, clamp the elastics underneath the head just above the neck (make sure it's secure)
-remove the S hook and the head, and the loops will stay at the top of the neck
This works well if you're working with the head only (like changing the eyes or something), the dolly sits around with a hemostat for a head for a bit, but they get over this trauma
If I'm working on the body and the head will be off for a while or I'm redressing the doll, I usually slip the S-hook back in the elastic loops at the top of the neck and unhook the hemostat (you then basically have a doll with a hook for a head). When I'm ready to put the head back on, I do the following:
-pull up on the S-hook
-reclamp the hemostat on the elastics so that there's a loop (make sure it's secure)
-take off the S-hook
-thread the elastic loops back through the head opening
-rehook the S-hook inside the head
-release the clamp.
It takes a bit more work than the "turn and pull through the head" type of attachment, but it's an option for those of us who don't want to mod the head.