Replacement of front screen & back glass?

I recently purchased a replacement kit (screen included) for the front of my Samsung S20. After removing the case to begin the replacement process, I discover that the back/side of the back glass is broken as well. Now im unsure if I can do anything without causing more damage to the phone. Should I wait to replace the front until I have a replacement for the back glass as well? And if so which one should I begin with when I have all the parts that I need? I've looked around but cannot seem to find much about replacing both of these so any direction or information would be greatly appreciated. Thank you