Some people have to be awakened with an alarm clock and others wake up when they want automatically.
In order to do away with your outer alarm clock, you have to learn how to make use of your 'inner alarm clock.
' As you relax in preparation for sleep, visualize the face of a clock.
Mentally move the hands of the clock to one minute before your real alarm clock is scheduled to go off.
After getting good at waking up at that time, you will have no need for physical alarm clocks.
As a daily exercise, look at your watch, then for the next hour, periodically guesstimate the time, then afterwards confirm.
Then, at odd hours during the day, catch yourself before you look at your watch and guesstimate the time, then check your watch to confirm.
With enough practice, there is a certain 'knowingness' that allows you to accurately perform in this manner.