I have a new cartridge to install for this single-handle kitchen faucet, but I need to know what tool is used to remove a part under the handle. Please excuse my ignorance of terminology! Under the handle is a large brass nut that retains the cartridge. I borrowed the tool to remove it (much thinner than my automotive sockets), but it will not drop into the body of the faucet because of six chrome-colored tabs that extend inwards just above the nut. I assume there is another tool required to remove this part before the retaining nut can be accessed.