I got an old bike from my dad and i need help adjusting the seat. The model is the Mongoose MGX D50i?

the seat is waaay too high and i want to bring it down but i can't seem to figure out how to do it. I would also like to raise the handlebars if that is possible. I've searched for users manuals online and i've found nothing hopefully one of you is familar with this model and can help me