How to change one's mindset?

Dude, being a tomboy is way funner than molding yourself to fit in with prissy girls who only want to talk about their crushes and how other girls are interfering with their crushes. If you don't like doing girly stuff, don't do girly stuff. Don't feel insecure or like you need to change just because you're different from your peers. If you like your friends, stay with them. If you don't, find new ones. Just don't feel like you have to change for them, or for anybody. I'm sorry that I didn't really answer your question, but I just hate that anyone would want to change their fundamental selves.

yeah be yourself if you are considering changing mindset, purchase some books on self-improvement.
If you cannot, then leave it be, because it is sort of difficult to change a certain mindset to another one. You are who you are, right?

It sounds like maybe you act like a guy without knowing it? Hmm, I suppose you could hang around them, and do what they do, and maybe it'll change. But there isn't anything wrong with being a guy, or girl. You are you :)