I did try snap ring pliers. Would not do the job for 2 reasons.
1. This spring is extremely strong and would likely destroy a good snap ring tool.
2. I could not get my pliers to not slip off the ends of the spring as soon as I tightened them at all.
Perhaps there is a model of snap ring tool that might do the job,,,i only own a couple but decent pair.
The vice grip trick did work quite well,,,a little practice could be done in a minute or 2. Likely however a once in a lifetime need unless you are in the business.