Pune to Solapur Commute

My friend is coming to Pune on 31st and has to go to Solapur the next day. She is coming to MH for the first time. hence has some questions regarding travelling.

Would it be better to take public/private bus to Solapur or go by train only? If anyone has travelled to Solapur before, please share. Are there any bus stops near Viman nagar from where she can board the bus to Solapur?