I got those bump stops installed several weeks ago, when I did my cheap mods to my suspension and steering. Turns out they were a wedge-fit in the cup. There's a couple cut slots, almost like louvers in the rim of the cup that grab the base of the foam beehive. So I cleaning things up, sprayed a little silicone lube on things, got the far side locked in and then worked the near side in with a rounded pry tool, came out fine, easy swap. And all I had to do was pry out the old ones.
failed to mention it earlier, REALLY like the fitment on the winch, in your bumper. Did you know your winch dimensions before designing / building your bumper, or was it a happy accident? I'm thinking the former as it all really goes together nicely.