I presume the bearing is grease filled. Most are. And, given the axle is a mighty hunk of steel, it's probably a pretty good heat sink. So I probably will end up trying to heat the retainer first and see if I can persuade it to shfit at all, while keeping an eye on how hot things get near the bearing.
One of many annoying things s that—even if I get the retainer suitably heated up—it's been hammered right down so it's resting against the ABS ring. So I can't even get any kind of pry bar in between the two, to try and get a bit of wiggle leverage.
All this hassle for a bloody metal ring that's been knocked on about a cm too far.