Here's a little device/tool that I made for pulling and reinstalling my hood spring on my '56 GMC. The materials could have been a little more stable but it worked long enuff to "git'er done". The leverage that you have makes it effortless.

All you do is place the end of the rod/pipe/bar at the firewall to where it is stable, cut the chain and spread the end links, position the chain over the bottom lip of the spring and then pull down on the opposite end of the rod/pipe/bar. Reverse the process for installing new spring.