I don't have a featherbed framed Norton
to look at, but I have always used a Motion Pro spring puller on my Triumphs, BSAs, and Commandos. https://www.motionpro.com/product/08-0127
This particular one is ground down on the hook end, my last one is not, and looks more robust. Or you can go to a motorcycle accessories store that deals in motocross bikes, all of the modern ones use springs on their exhaust pipes and they will have brand alternatives--look for a welded one that looks strong, with a good T handle. Unless you are built like Arnold Schwarzenegger, you might want to sit down next to the bike with it on the stand, brace your foot on the stand, and pull--oomph!
The alternative, which may or may not work depending on the particular motorcycle, is to remove the pivot bolts, install the spring, and then use the center stand as its own lever and reinstall the bolts. Not as fast or simple as simply sitting on the ground and pulling it on with the spring puller.