Employee training can be greatly enhanced by using praise and positive reinforcement to boost self-confidence.
It is normal for people to lack confidence in learning a new task. The more complex the task is, the greater the doubt the person may have that they can learn and perform to expectation.
Breaking down the training by steps and giving praise and positive reinforcement when the employee successfully completes a step will greatly boost their self-confidence and belief that they can keep learning the more complex steps.
When the employee fails to do the step just keep it positive and have them do the step again or break it down even further. Keep communicating your belief in their ability to learn and perform the task.