Ignition lock defective

Dear V8 ́ler, the last construction site has not yet been fixed, since the next one is already blooming. Yesterday, I wanted to get the fat guy out of the garage, and I always turn on the lights. But... Light is not working, only a glimmering funzel is visible. Then I realize that the air conditioning is dark, turn signals don't go either. At the front of the hood, it sounds like neighbor's cat is sitting under it. Shocked, I quickly turned it all off. What is now ???? Then in the evening, tell my husband the great news. Then he found out that the starter stopped at the start. Normally the key goes back a little bit when the engine has started. That was no longer the case. So the starter's running along all the time. The key manually turned back a little, already neighbor's cat was quiet and also light, turn signals and the climate were alive again. However, this is now not a permanent state. Has any of you ever changed an ignition lock? Or it says : Keep your fingers off it and visit the dear workshop. Doing it yourself would be better for us to *grins* Is there a repair instruction ? Unfortunately I found nothing in the forums and FAQ.
Best regards
Claudia