Whats the Best way to turn 100k into 5k a month income, legally..?

That's a pretty high return: 60%. I would say you need a salable skill and spend the 100k on tools of the trade.

You are not being reasonable. Even a 6% annual return on 100K would return $6,000 or $500 a month. You can't be naive enough to believe anyone would offer $5,000. a month when the current rate is closer to $500. a month. Get real !

Thats 60% annually. If there were any guarantee like that, nobody would be poor.

Honestly, learn to play poker. With that bankroll I could EASILY make 5,000 a month.

That is going to be hard. My best ideas are below.

Put it in a shoe box.. you can take $5K / month for 20 months.