It is impossible to swap schools without your parent's approval and permission. You will need your parents to gain transfer forms from your old school and to be admitted to the new school. In the absence of your parents you need your guardians.
It is NOT possible for a minor to change schools without a parent or LEGAL guardians permission. Not just "permission"-they have to be the ones who does the transfer - with I.D. (and court papers -in the case of legal guardianship)