Transferring to another University is a complicated process, yet the steps are very well defined on University websites and many students take advantage of the process.
A full application is needed for transfer students, although you may request a waiver on a few requirements like TOEFL. You should do very well in the first semester in your current US University, preferably all A’s. This cannot be stressed enough. In your Statement of purpose you have to give a good reason on why you want to transfer. Focus on the positive aspects of your target University rather than mentioning anything negative about your current one.
Common (and acceptable) reasons to get a transfer:
The desire to graduate from a more reputable University
Better research opportunities
Better funding opportunities
Personal reasons like being close to your significant other