Good luck Mantilla! Look forward to hearing how you went. If you haven't done a butter under the chook skin before, I take my time loosening the skin as it's easy to put a hole in it if you have long nails (speaking from experience lol). and I have a teaspoon with a smaller bowl than some of the others and it seems to work better. If you make your own stock, the carcass makes a great stock afterwards.

I have a large tablespoon and the end of the handle is rounded and fairly flat - absolutely perfect for getting under the skin of poultry without tearing it.

I actually use sticks of butter, and use my fingers

Disposable gloves and fingers - I can't bear to squidge unprotected fingers into a chicken.. somehow the gloves make it tolerable