Capital Gains Question

[Kate McDevitt]

Hello!

I've been rehabbing my uncles house for the last year and I am about 6 weeks away from listing it for him. He just offered to put me on the deed and give me all the proceeds of the sale.  How do I avoid getting hit with massive capital gains?   We will likely sell it for around $700K.  

Both my uncle and aunt are on the deed and lived there for 25 years and there is no mortgage on the house.  

I had it appraised before I got started and it came in at $500K.  My uncle paid $180K for it 25 years ago. 

All help welcomed!

Thanks!