Yanking barend plugs out?

I'd like to pull out the rubber expander plugs inside my handlebars so I can
fill them with fishing weights. I already used a 6mm bolt to slide them all
the way to the opening with the claw of a hammer, but then I get stuck
because the hammer butts up against the plug itself. I can't move it out
any further, and I can't just pull on it and get it to move.

I was thinking I could get another short length of pipe to "extend" the
handlebar, thread in the bolt, and use the hammer trick again, but I don't
think I have anything of the right diameter at home. I'll try the trick
when I get back to work.

Anyone have any ideas?

 

Look through your collection of sockets. There's often one of
about the right diameter. You could also try some Kroyle or other
penetrating oil. You don't really need an exact match to the
diameter either. A slightly larger size would still give you a
good fulcrum.

 

Go to the hardware store and buy the longest metric bolt with the right
thread you can find, maybe 9 inches to 12 inches long. It might be
threaded all the way. Get a big washer, and slide that on. Slip a large
deep well socket over the bolt. Thread the bolt into the expander plug.
Leave plenty of room for the socket to slide on this home=brewed slide
hammer. Grab the socket firmly in one hand and slam it against the big
washer repeatedly until the plug pops out.