Set for life requires you to get $1,000,000 from playing contracts mode. You can get some easy money to start off with by creating a contract and then by following the Partners in Crime solution. You can have your secondary account make a few easy contracts that you can get some money from.
However, after a few contracts, you'll stop earning money from playing the same person's contracts so you'll have to go play other contracts. I found that most of the easy contracts were on Terminus - Upper Floors. Go to Quick Play --> Find Contract and when the list of contracts come up, hit the Y/Triangle button to filter the contracts. Choose the map you want and then choose Popular. The ones that make a lot of money quickly tend to be most popular.
Pick a contract that seems like it is pretty easy and play it. Keep in mind the base pay out as well. The pay out is dependent on the number of kills and other conditions present. For instance, killing three maids without leaving a trace and while using a specific weapon and costume will net you far more than killing three guards if you are spotted even one time. Keep this in mind because it means that a high payout doesn't always require a difficult contract.
When you've made a million, you've got the achievement. Now it is time for the Self-Improvement achievement.
