You want to bleed the entire system without introducing air into it. Use a tire iron and have a buddy compress the surge brake three times and hold it. While he is holding it release the pressure on the bleed valve of the farthest brake cylinder, usually a 3/8" open end wrench. Put a rubber hose on it unless you don't care about making a mess. Also, brake fluid is caustic so the hose helps there also. Once the pressure has dropped and stops spraying out close the bleed screw and have him pump it 3 times and hold again. Continue this until you have clean fluid coming out the bleed valve, remember to keep the reservoir filled or you will introduce air into the system. Once you have clean fluid coming out of the farthest bleed valve refill the reservoir and go to the other brake bleed valve and do the same thing. Be sure to use the Dot 5 and check your brake shoes and hub bearings while your at it.