Visit the school and see if they will give you permission to enroll.

Find a special program in the new school that is not available in your present school and indicate that a reason for the transfer is your strong need to take that program.

In many cases the high school that you attend is the one that is zoned for the geographic area in which you live.

All of that said, why do you need a new school. many who go to new schools fall into the same patters of attendance, work and discipline problems that they had previously. See how you can alleviate the problems that you may have. Running away frequently is not the answer but just an escape.