well it's not rocket science but here's how we did it...
short term when I had to be out for bedtime for some reason, the only thing that worked/works was for me to go out and the child to see me go out - wave goodbye from the window, watch me go down the street etc.
If they had even a suspicion that I was in the house, it never worked - they would just scream until I came.
Dh would then try to put them down, they'd often refuse, but he didn't let them scream for too long (I think that's counterproductive as the child gets inconsolable). Instead if it wasn't working he'd get them up, take them out of the bedroom, they'd have half an hour more quiet cuddles and play, and try again. Repeat if necessary but almost always worked on the second try.
In your situation I guess you'd have to go for a drive or a walk if need be, but you could creep back once they were asleep.
Actual true night-weaning took much longer (and we haven't done it yet with DS2 who is only 16 months) but what we did with DS1 was first to get hm used to DH putting him down, so I'd always call DH after the final feed and DH would be the one to physically put him in his cot. Then we tried to break the association with feeding and sleep - so we moved stories and toothbrushing to after the bedtime feed, and again, DH would put him in his cot.
When that had become routine, we started getting DH to go down every time DS woke, and trying to get him back to sleep. It didn't always work and if it didn't, I'd go down and feed. I know some people prefer to do a clean break, but I felt DS wouldn't understand that, and this way was gentler for all of us.
Eventually DS got more and more willing to settle for DH, and finally it got to the stage where I could go down and settle him without a feed. The whole process took about 6 months and he was nightweaned by about 26 months I think.
He still fed morning and evening for quite a long time after that but at about 28 months I went away for a full weekend and DH had no trouble and I didn't need to pump or have any discomfort. We just resumed quite happily when I got back.
Hope that helps - none of it's very original but it did work and it felt quite natural and not too distressing for any of us.