You think they are difficult to restrain, mainly because of their understanding of rules and organizational discipline, and your role in the work is not accurate.

I suggest that you can grasp these three points first:

One is to help them set goals (such as excellent technicians), so that they can understand what they can get, how to do it, formulate some standard work processes, how to become an excellent technician, etc., improve their work attitude and cultivate their sense of service;

Second, use the system to manage their work, restrain their behavior, and pay attention to the fairness of the reward and punishment system;

Third, it is emotionally humanized, which can appropriately lower its status, care more about the details of employees and win the trust of employees.

In fact, employees are older and have low academic qualifications. They have certain management advantages in technician positions, and their work is relatively stable, so there won't be so much uncertainty. Besides, this is your first time to participate in independent management. In the case that your current ability is temporarily insufficient, I suggest that you can find professional staff training to supplement your knowledge and let yourself quickly integrate into the team and post.