Augmented Reality (AR) is an emerging technology offering a great potential in assisting humans in a wide range of industrial processes, from manufacturing to validation and maintenance. However, very few AR solutions have been adopted so far in industrial sectors, mainly because of technical and acceptability issues. This paper has three main contributions: (1) it identifies potential barriers for AR adoption in manufacturing environments; (2) it proposes an AR training methodology that overcomes these challenges and finally, (3) it evaluates the proposed AR training approach in a concrete, real-world use case by conducting a field experiment with 12 participants. Our findings indicate that low-cost assistive visual assets (i.e. text, images, videos and arrows) can be sufficient for effectively delivering complex manual assembly instructions through AR head-mounted displays (i.e. Hololens 2). We finally discuss how the proposed methodology simplifies considerably the authoring of the AR instructions and how this technique can potentially be generalized to other similar industrial scenarios.