Strategies for Taxes on Long Term Sale?

[Jackson Tate]

My dad is going to be selling his home soon, a house he has lived in for almost 40 years. He will more than likely be able to sell it for close to $2M, and his basis is probably around 500k. This sale is what is going to help him be able to truly retire, so I'm trying to find any available strategies to him to eliminate as much of the potential capital gains as possible. He does plan to use some of the proceeds to purchase a new home, but it will probably be 1/3 of the value of his current home, so I'm assuming no sort of exchange applies. Any tips or advice would be greatly appreciated.