Hi @Obeti
It is possible to change Ausbildung. You need to have a contract for the new Ausbildung and then submit it to the immigration office (Ausländerbehörde).
There isn't an Ausbildung for engineering. In order to become an engineer, it is necessary to study at university. There are, however, many types of Ausbildung in the technical field. Here is a good overview of different types on offer:
https://***.ausbildung.de/berufe/themen/mit-technik/
Best,
Éanna