I'm having trouble telling if the threads are part of the router bit or collet. I'm guessing the collet....
Get some thin angle iron from the hardware store. Drill a hole and machine screw through one end. Now you have a "V" with both pieces of angle facing up. Use that V on a vise and have it pinch between the bit and the collet. Then you can take a nail punch and tap on the collet. If the threads are part of the collet that won't work but you can then flip the bit/collet around and take a screwdriver and tap in the slit of the collet just a little. If you have a workbench with dog holes you could use that instead of a vise. I wouldn't tighten the angle too much either because technically they'll be on different planes. The slop should help compensate. Hope it works. I had a friend push a router bit all the way in and it was a bear to get out.
The other idea is similar. Put 2 nuts with a large washer between them. Put the lowest washer in a vise and use a screwdriver to pop the router bit out. You could also use the angle iron or aluminum angle V from above. Personally I'd use aluminum due to it's softness.