Share 'How to lift the purlin'?'

We are building a log cabin, its 30x25ft built from D milled 6x6” logs. I have felled 3 32ft trees to use as purlins, they must weigh 600-700lb. I have no idea how to lift these into place. How is it normally done? I just got a cost to rent a crane and that came in at a un-affordable $1,100.   How am I going to do this?