I would recommend taking your device to a local UBREAKIFIX location to get your device in the hands of a certified tech to assist you with this. It will either require service or the tech could be able to remove the s pen for you. You can search for a location by using the link below.
If you would prefer, you do have the option to send the device in for service, if you would like me to set that up please send me a private message with your model code and IMEI number. https://bit.ly/2SUXRar