Put one end of the spring over a solid peg and use a bar in the other end to stretch the spring then place tapered wood shims in the gap between the coils...this will lengthen the spring enough to where it will install with little effort. Once the springs are installed, close the hood slightly to allow the shims to be removed.
Agreed, Although I usually use large diameter (matching the spring outside diameter) hard nylon/plastic washers between the windings/gaps on a stretched spring (add just enough washers in the stretched windings so the spring is long enough to comfortably fit on the raised hood hinge), hood hinge fully up, then fully close the hood, most if not all the plastic washers will drop out with the hood closed/spring fully stretched