Is it possible to reset MMR or drop to a certain ranked division on purpose?

Copy>paste of my ticket, that I tried to send to the Blizzard support, but I couldn’t for some reason:
I am having an issue with my MMR in Ranked games.
I used to play a while ago, when the Ranks system was still in game (ranked games), I managed to reach Rank 1, which was the highest rank achievable. I haven’t played in a while, I am not familiar with the game anymore, but I am having a lot of fun playing it with my friends. We played 3 placement games together, they got to Silver/Gold and I was instantly in Diamond 3. Now I cannot play with them anymore, because my rank is too high. Also, other players in Diamond 3 division are just way better than me, because as I said before, I am not familiar with the game anymore.
Could you reduce my rank or reset my MMR? So i could drop to Silver/Gold and play with my friends.
Thank you!