i do number 3 by elevating my foot on a chair and just stretching the ole hamstrings w/ either a bent knee or a non bent knee. NOTE: BACK STAYS FLAT WHILE STRETCHING. next get a golf ball/lacrosse ball or a new tennis ball and sit on it on a chair w/ your high hamstring. NOTE: BACK STAYS FLAT AND LEG MUST BE AS STRAIGHT AS POSSIBLE.
for number 4 google it. and just lie down on the floor and place a golf ball under your ass in the piriformis area.