How do you move and transplant a 4 foot Fir Tree?

We live in Oregon on 7.8 acres... California city transplants. I walking around the property I have noted several Douglas firs or White pines that are growing in spots that will led to their demise... One is 8 inches tall and growing under the edge of our house. The other is 4 feet tall and if left in its present position, it will have to be cut off as it is under some low hanging power lines. I want to move it to the other side of the property near a pond. A third is in amongst some rocks that will be cleared for a road to a wood lot. My questions are how much of the root do I have to capture and is there anything I can put in the hole at the new site that will help to generate root growth. I intend to stake them for awhile to support that. Should we tamp the soil or leave it a bit loose. Appreciate any help or sites where we can gain this info as I hate to see them go to waste. Help me save the little guys. Thanks again