1) What you need to have is at least 4 characters total: 3 tank characters and 1 boost character (recommend you have 6 characters available and 2nd group of players with 6 characters available for easy wintrading)
2) You tank 3 characters to say 500mmr or anything really low
3) Switch boost character to the tank team
4) So what you have now is one guy at say 2000 personal mmr and 2 guys with 500 personal mmr
5) You start queuing normally or wintrade, whatever suits you
6) When you queue up, you will meet teams with 1000-1200 mmr
7) What happens when you win is that your boost character gains about 200 personal mmr per win
Keep winning or wintrading up until 5-10 wins (should be easy as it's 1k mmr players)
9) Now when your boost characters mmr is at 3.5k-4.5k, depending how long you will keep going, switch the boost character to your "main" team
10a) Now, you will be playing at 2k mmr again, but this time your boost character has 3500-4500 personal mmr, so every time you win you will gain +192 rating up untill around 3.3k rating. You can also wintrade this, but I think it's relatively hard at 2k mmr as it's pretty active 24/7
10b) If you have a lot of friends and decide to wintrade you can get all of your mmr to close to eachother at 4k for example and wintrade yourself up from there. You should be gaining +192 rating per win up until 3.8k mmr. Obviously this is easier to detect as you will mostly be fighting against eachother at super high mmr, but I decided to list this aswell as it's one method
11) Rince and repeat, after a while and few wins you should be really high rated
2) You tank 3 characters to say 500mmr or anything really low
3) Switch boost character to the tank team
4) So what you have now is one guy at say 2000 personal mmr and 2 guys with 500 personal mmr
5) You start queuing normally or wintrade, whatever suits you
6) When you queue up, you will meet teams with 1000-1200 mmr
7) What happens when you win is that your boost character gains about 200 personal mmr per win
Keep winning or wintrading up until 5-10 wins (should be easy as it's 1k mmr players)
9) Now when your boost characters mmr is at 3.5k-4.5k, depending how long you will keep going, switch the boost character to your "main" team
10a) Now, you will be playing at 2k mmr again, but this time your boost character has 3500-4500 personal mmr, so every time you win you will gain +192 rating up untill around 3.3k rating. You can also wintrade this, but I think it's relatively hard at 2k mmr as it's pretty active 24/7
10b) If you have a lot of friends and decide to wintrade you can get all of your mmr to close to eachother at 4k for example and wintrade yourself up from there. You should be gaining +192 rating per win up until 3.8k mmr. Obviously this is easier to detect as you will mostly be fighting against eachother at super high mmr, but I decided to list this aswell as it's one method
11) Rince and repeat, after a while and few wins you should be really high rated