Welcome to HCM!
I have read your question carefully and from my clinical experince I can tell you that after you hurt your toe some time back, the old nail started dying and a new one started forming beneath it.
The new nail will slowly ( in 6-8 weeks) will grow fully and automatically the old one will shread away.
It is not recommended to do anything with old nail, as it may hamper the new soft nail growing underneath. Only in cases of fungal infection/ diabetic /
redness and pus discharge patients , etc., the intervention is required.
So, had I been treating you, I would ask not to do anything with any part of either the new nail, or the old one. The nature will take care of it, and after sometime you will see a full grown new nail and old one will spread.
Good luck and donot worry!
Feel free to ask more questions.
Dr. Manisha Gopal