talley_Sue, hopefully not too late. You should be able to replace them. Typically they are just knocked in with out fasteners or adhesive. They would be difficult to just pry out from the center as there is no room for movement. Being that you seem to be pretty handy, I would recommend taking a couple of nails and tap in at two opposite sides into the wood at edge of adjuster and start to pry up with equal pressure. Keep prying until it comes out or you can grab the adjuster with pliers. Hope this helps, Tony

don't bother you'll drive yourself nut. - what you need is a brad point drill bit just a bit smaller than the diameter of plastic plug which is 20 mm.

3/4" ought to be easy enough to find and you can just eat away the plastic plug with a battery drill.

xedos, IMO that's bad advise. For the following reasons. For the homeowner/non professional it would be best to suggest something with tools and methods most likely on hand and least chance of damage and or injury. 1st a 3/4" brad point drill bit is not a common item for a homeowner. I don't even have one. Instead I have a 3/4" Forstner bit. Your drill method poses many potential problems. It can be dangerous in inexperienced hands, you would absolutely need to clamp the drawer front down before drilling. There is a real potential with that type of bit and non solid uniform plastic to get a kick back/wrist twist if it grabs the plastic/metal unevenly (i.e."just eat away the plastic"). Also the center hole of the Blum adjuster is too wide for the center of the brad point to even work. The bit will swim around making the situation even worse. Then there is the issue of accidentally drilling through the drawer front and into the surface underneath.

Rather than two nails as I suggested, two thin blade regular screw drivers should work. Far less time, expense and risk of damage/injury.