If you have been out of school for more than a year you may need to re-apply at www.applytexas.org . Check with the college to see if they can reactivate your files or if you need to re-apply.
If you have not ever attended you will need to apply at www.applytexas.org
There will be an application fee required when you apply. Check with the college for the amount.
Check out the application deadlines and make sure you get your paperwork done early.
Entrance testing may be necessary for some students. Check with your college to see if it applies to you. If so make arrangements to take whichever tests are required.
If you have attended college at a different school it will be necessary for you to have a transcript sent to the college you are now applying to.