You don't have the correct training. Most manufacturers' courses take a couple of days and cover the entire range, not just a single model. We are not in the business of selling training. There are commercial organisations that do very thorough training courses covering all aspects of servicing and repair. We don't recognise any courses but our own.
Lets take a step back from the specifics of diving equipment and take a wider view of things.
None of the rules manufacturers are hiding behind are specific to the diving industry. I can't list them all. The rules apply equally to all work environments, but not outside them. I can go to the local DIY shop and buy all the potentially lethal electrical bits and pieces necessary to re-wire my house. If I made a mistake I could easily electrocute myself, electrocute someone else, or even set fire to the entire street.