Anyone know an easy way to replace a sagging floor joist?

Anyone know an easy way to replace a sagging floor joist?
If you have access below the floor to install another joist, try this:

1. Jack up the sagging joist in the center slightly above level.
2. Scab on a new joist along side the old. Set nails or sheer screws every 12" minimum.
3. Install freeze blocking to adjoining joists.(Those joists may be sagging and need scabs.)
4. Release jack slowly. Have someone above floor monitoring the carpenter's level.
5. Best way... put in a new support girder at span midpoint for all joists in crawl space.