Above advice works good
I'd like to add my 2cents here. I've used the sharpened popcicle sticks, plastic putty knifes, orange sticks, bamboo skewers and metal dental picks. All work fine. The best stuff is aerosol gun barrel scrubber. Used to use Hoppes #9 but its no longer available in the silly state of CA. WalMart and KMart have plenty of another brand. This stuff, if it doesn't liquidify the vulcum, at least will soften it. Once the old is removed by whichever tool works best for you, I tape off the seam on both sides and apply the vulcum using a syringe and force into place with a finger. The finger is in a latex glove mind you. The aerosol spray on a paper towel will remove any excess you don't want.