Don't make any marks on the spring with plyers or eventually the spring will break in that spot, that goes for any spring, especially brake springs.
A pictures worth a thousand words.
I have used a bent piece of coat hanger pulled by a ratchet strap connected to the I-beam.
Where can I find one of these, nothing shows up on the interweb? Failing that, does anyone know what the spring rate (i.e. pounds/inch) is for improvising something? My current spring is only 80% complete.