How to delete a collector?

I deployed a few remote collectors to evaluate some things when compared to just using the vApp. I've decided to stick with a vApp only implementation of vCOps and have retargeted the different vCenters back to the vApp. I now have the standard 'vCenter Operations Standard Server' collector, which all vCenters point to, but I also have a number of other 'vCenter Operations Standard Server' collectors that were added while I was testing remote collectors. How do I remove permanently remove them from vCOps?  Screenshot attached. Running vCOps 5.8.1.

-Josh