1) Get yourself a Swedish TD (You can also use any TD with 280+ pen but you will have to use gold and probably will get spotted)
2) Position yourself in the red spot
3) Farm the target (it has enough pen with standard ammo to pen it from that range and that angle) + make sure you don't get spotted
4) Profit
They will have no idea how is your team able to damage it and start rush towards you if they are not dumb so be careful. Don't stop shooting because with 3k DPM it goes down in about a minute.