I currently work in Munich, and I moved here with a Type D visa for the purpose of work(contract for a year). I currently have an offer that will make me eligible for a blue card. What exactly is the process shifting to this and who do I have to inform once I have resigned from my current role?
If you are already in Germany with a German residence title, you can apply for the EU Blue Card at the immigration authority that is responsible for your place of residence.
Source: The EU Blue Card FAQs Federal Office for Migration and Refugees https://www.bamf.de/EN/Themen/MigrationAufenthalt/ZuwandererDrittstaaten/Migrathek/BlaueKarteEU/blauekarteeu