Hope tandem rear hub instructions

[NickJP]

I've acquired, 2nd hand, a Hope tandem rear cassette hub (40h, 140mm rear spacing) to replace the existing freewheel rear hub on our ~40-year-old tandem. The bearings in the hub still all feel fine, so I don't need to service or replace them, but I want to move the Arai drum brake from the old hub to the replacement hub, and it's not at all apparent how to split the non-drive side endcap to fit the brake in place. In my photo below, you can see the spacer between the two halves of the endcap - that's replaced by the housing of the brake when one is fitted to the hub. Does the endcap pull off or unscrew? I've tried a moderate amount of pressure for both options without getting it to shift (things may be a bit corroded in place as the axle is steel), and the Hope website doesn't have anything among their service documents for this hub. Has anyone had this hub through their hands in the past and have any suggestions/instructions?

[Brucey]

most hope hubs have end caps that just pull off, courtesy of a hidden 'O' ring. Commonly this pulls off easily when the hubs are new, rather less so in older hubs. I don't have experience of your hubs, but that is how I would expect them to be put together. You may need someone handy with a lathe to make fittings suitable for your arai.
FWIW there is no point in overhauling knackered bearings, so the time to add fresh grease to the bearings is now.

[Redvee]

If you can't find the instructions on the Hope website, contact them direct via email and you should get a response in a day or two.

[OutdoorOasis]

try applying penetrating oil around the endcap joint to loosen it up. Sometimes a gentle tap with a rubber mallet on a wooden block can help.