This achievement requires you to reach the first level of infamy. There are only two requirements necessary for going infamous.
1) Reached level 100. (this is also another achievement on its own)
2) Currently possess $200,000,000 in offshore cash.
You'll need the offshore cash as a buy in to going infamous and reaching infamy level one. On the main menu after meeting the requirements, "BECOME INFAMOUS" will become an option. After confirming, the achievement will pop and you'll be reset at level 1-0.
- For gaining EXP, I highly recommend tackling rewarding heists such as Hoxton Breakout, Hotline Miami & Bomb: Forest. Having stealth EXP bonuses & leveling up at least one perk deck are great ways to quicken the process.
- For gaining large amounts of cash, cooking bags of meth on Rats & Hotline Miami, farming bank heists, The Bombs & Hoxton Breakout are all great techniques of earning cash.