I love this girl as a freind, now I want to make it into a relationship, how?

Ok, so I know this girl for almost 2 years now and she comes to the same college as me and I see her mostly everyday. Her mates are the same as mine, and we laugh and joke together and have fun. My mates have known her for longer and are obviously more closer to her, she hugs, kisses and plays around with them more, and to me its mostly just a hug. Ive fallen for her because of her personality and her childish and bubbly character but for me to become one of her best mates is quite hard, as im just a 'quiet' and 'cute' freind to her. Im very open to her and I care for her alot, but in a situation such as e.g. me and her hugging, if one of my mates comes to say 'hi' she would hug him tight, kiss him and joke. I obviously feel some jelously but knowing that its one of my mates I cant do much to stop her to do that stuff to me. I would speak to her one to one saying how much I really like her, but its awkward because I dont think she feels the same way as I do to her than she does to me. She's more quiet than playful to me and I want that to change to build our freindship as we are gonna know each other for quite long. People say I should drop the line and ask her to go out with me, but it wont feel right as mine and her mates are more closer to her at the moment as theyve known each other for longer. We've talked about nearly all the topics such as hobbies, freinds etc but it doesnt seem to make a difference. I text her mostly everyday but it usually me the one who starts it, sometimes i get long replies and sometimes i dont.

I just want some advice about what to do to make this change happen,
how can I build her trust towards me?
how can I make her more childish and fun towards me?
and how can I make her love me?

Thanks

You can't force her to like you. But as of now, you don't know if she does. The only way to know is to ask her. Ask her to do something without the group and just have a nice, yet casual, conversation with her about the possibility of you two dating.

Good luck.