Magic works in subtle and nonphysical ways. So no, magic isn't going to help you transition into your preferred gender.
Now it can help you feel more confident in your changes, bring you motivation or opportunities for hormone therapy or surgery, and so on. Magic works with the mind and through the mind, not the body directly. Magic works through the non-physical, not the physical directly.
If you don't know that, look it up. If you are serious and this is how you percieve yourself to be--what ever being a boy and your gender means to you, mail and friend me and I can explain a great deal of all of it to you.
I myself am a transgender, but you may always have been born, biologically, as a female with a genital and a brain and hormones that of a female.
If you have gender dysphoria and wish to change this to match the way you experience gender, you can take hormones or have a sex change, etc.
There's a lot of resources on tumblr and around the web, and I'm more than glad to help you if you are confused or etc on how to grow into yourself and to truly represent yourself in any which way you chose to math the gender you feel that you are.
Keep in mind that gender is social, and contains things like roles in society, and how you generally perceive yourself--it is separate from the way you express yourself and choose to dress--separate from the way you choose to be called and refered to--different from who you are attracted to sexually and/or emotionally--different from you who were born as--and different from your biological sex which deals with hormones, the way you think, etc.
But no, magick cannot transform you if you are truly transgender, but I could reccommend trying to meditate, prayer, etc on finding ways to accept yourself and ease any anxiety or gender dysphoria you may have, and also on the hatred and transphobia others may expose to you, be it physically or emotionally.