fuel pump lock ring removal tool
 

I have a 2005 Chrysler 300. I was able to remove the transfer pump lock ring using a hammer and flat tip punch. The o-ring was leaking (old style) replaced with new style, round o-ring. I have not been able to tap the lock ring to its original lock position. Has any one used a lock ring removal tool that works. Summit shows a OTC 6599 that looks like the right tool but says it is for a 5.250 in. lock ring that is about the size of the inside diameter and the outside diameter is 7.250 in. The indents for the tool are on the outer edge. Has anyone used this tool? I am new to the site and did not have any luck using the search feature.
Thanks, Bobespo