I left a company several years ago. Can I roll out 401k and invest in real estate? How?

According to Section 408 of the IRC, you can purchase land, commercial property, condominiums, residential property, trust deeds, or real estate contracts with funds held in many common forms of IRAs.

The trick is finding an IRA custodian who handles real estate. But it can be done. Once you find such a custodian, you would simply roll your 401K into an account.

1) Roll-over (withdraw from) your 401(k) plan into an IRA roll-over plan.

2) Within your (roll-over) IRA, you can invest in several different real estate ETFs, or real estate-type stocks or mutual funds. There are many choices for you.

3) The realy tricky question is a) a "tradional" IRA or b) a "Roth" IRA. If you are eager to "get rich quick", chose traditional. If you are over 45 (nominal), I would suggest a "Roth"

Sure you can - as long as you are prepared to pay a rather stiff tax penalty. I doubt that you could make enough in real estate to make that up as you would also be paying taxes on whatever earnings you had from the real estate.

You can buy real estate investment trusts with you rollover IRA. As far as using the money to buy an actual property...I don't think so.