need to know best way to run sprinkler line under driveway, sand base

Without tearing up the driveway you would do the following

Dig two holes on each side of the driveway. The deeper the better.
Then take a long plastic PVC pipe that is 3/4" in size. On one end glue on plastic fitting that will hold a hose. Attach the hose to the faucet and begin to drive the hose under the driveway. The water will errode the soil in its path and allow for the pipe to drive through.
If you have access to a larger air compressor you can wye that into the line as well to add pressure.
This is a messy method but works well as long as you do not hit any large rocks etc. You may need to try diffrent areas to get the pipe under, but it works.
You should also consider attaching a metal wire to the plastic pipe as you run the pipe under. This way in the future if you need to pass an electrical wire to other side such as driveway lights its already there!

Once the pipe is through you then change the fittings on the end to match your existing system.