Put your index finger on the nib and your thump on the feed and pull, both nib and feed will come out.
That's what I've read, but I'm getting nothing! Not to mention my finger seems to slide on the nib more than anything.
Can I push from the back and force it out?
Do not try pushing it out, wiggle it as your pulling, I've never had one that wouldn't come out and never had to but you might want to put a latex glove on so your fingers don't slip. One question , is this a new pen or is it one that has been used and the ink dried, if so run the nib and feed under tepid water to loosen the dried ink.I have removed at least 100 nibs in the last year or so and never had one not come out. Every fountain pen I sell at a show I take apart to show the customer how to clean the feed.
You might want to check this article out. Lou knows more than I do!
http://content.penturners.org/articles/2007/nibreplacement.pdf
Hope this helps!
Put your index finger on the nib and your thump on the feed and pull, both nib and feed will come out.