Registering to vote is easy in Texas. It doesn't even require a stamp! Official applications to register to vote are postage-paid by the State of Texas. You may obtain an application from the Bell County Elections office in Belton, the Secretary of State's Office, some libraries, many post offices, or at a TxDot office.
Read the instructions on the form, fill it out and place it in the mail postage-free to the address on the form or hand-deliver it to the Bell County Elections office in Belton. You must be at least 17 years and 10 months of age on the date you apply.