Soldering to Cardas female RCA connector

I'm very new to the DIY audio scene, but I'm trying to finish the infamous non-inverting Gainclone amplifier and I'm having trouble soldering to the RCA connectors. They are Cardas nickel-plated copper parts. I'm not sure about the part numbers.

The signal conductor has a nice solder cup but I can't seem to find an appropriate soldering location for the ground shield. How am I supposed to accomplish this?
if its the one im thinking of, i do a little trick (i have no friends). i strip an excess of wire, wrap it around the groove, solder a place of the wire, and cut the excess off. no tricky plier-weilding needed and you dont need a third hand. they look like this:

yep, inside that groove.

you gotta get the iron HOT. i turn mine up quite a bit (forgot what temp). you have to hold it on there for awhile for it to get warm. usually what ill do is warm it up with the iron, melt some solder on it, then melt solder separately on the wire, then melt the two together. seems to work well.

just be patient, it just takes some time.