My glue applicator is glued; What should I do?

I would use a small drill bit the size of the opening and drill it out.  Make sure you cap it when it is not in use!

Thanks but I have done this too and it's not working. And I always put the cap on when I don't use it.

If you get a bottle of Tamiya Extra Thin Cement, your problems will be solved.  

Ok very interesting info but for now I will stick with this one because I have three new bottles from Testors.

The yellow seems to be a foreign substance or item in the tube. You have to get it out or drill it out. 

I replaced the piece of tubing in my bottle with a 22 gauge syringe needle. If you know anyone that is a diabetic and takes insulin, they can save a needle or two for you.

Hope that this helps.

Jim 

Stay Safe.

I spent more than one hour trying to remove and drill the yellow substance in the nose. It didn't work. I also cut the nose several times but the yellow substance is still there and the glue wont come out.

I would throw that bottle away since you have three others from Testors.  I'm not sure what you are doing to get the nozzle clogged up, but it may be time to rethink and re-educate yourself on gluing techniques.  If there is a foreign substance in there and you can't drill it out, then you are allowing something to get in there in the first place.