Small Engines (Lawn Mowers, etc.): Walbro WT-539 Mixture Screws Plastic Guard, black caps, plastic caps

Question
I am just starting a carb rebuild of a Walbro WT-539 carburetor from my Ryobi 280r blower.  Problem:  The Low-speed mixture screw has a white plastic cap and the High-Speed mixture screw has a black plastic cap.  How do I remove the plastic caps to allow me to remove the mixture screws to clean the carb?  The caps have a separate black plastic piece that fits over the white & black caps to disallow any turning of the mixture screws.  I don't want to break the white/black caps in attempting to remove them.  Thanks alot for the assistance!

Answer
 Hello Rodney:

 The Air Mixture Limit Caps are Designed to be Broken to Rebuild the Carburetor. New Limit Caps should be in the Rebuild Kit. You Don't have to Replace the Limit Caps. You can View a Breakdown/IPL of the Carburetor at this Addy http://walbro.com/ and Select the Service and Aftermarket. Then Select Aftermarket Parts and Service. Then Enter the Carburetor Number into the Box Search by Walbro Part # and Click Go. Then Click on the Model in the Search Results Area. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks. Be Safe.

 Good Luck

 Respectfully

 John

 PS:  Happy Thanksgiving and Merry Christmas (:-))