L.A.

Hello all. I have a mercedes A250e limousine 12/21 and it charges with 3.6Kw max. I asked the dealer if there is a way to charge with 7.4Kw and they said it can be done (600 euro) and it's a software update . The code for charging at 3.6KW is 80B while the code for charging at 7.4Kw is 76B. Has anyone upgraded to 7.4Kw out of dealer ? Can someone retrofit this code update and to give instructions so that others in other countries such as Greece can also do it;
Thank you.