Number portability from O2 to other provider immediately

Hi O2 team, 

I would like to take my current mobile number from o2 prepaid to another provider for my new contract. Could you please release my number for porting immediately? 

Even though this page says I can do it via App or MyO2, I couldn't find it anywhere: https://www.o2online.de/service/vertrag-tarif/rufummermitnahme/

Thanks in advance and waiting for the number release. 

Update: I have canceled all active plans and my available current credit more than 30€, payback the rest to my account. 

Edit o2_Vivian: verschoben von SIM-Karte zu English o2 Community: Mobile