How do I change the cartridge in my kitchen faucet? it has hansgrohe 01008 stamped near the base. Purchased August 2008. I can loosen a set screw on the handle but I cannot pull the handle off. I have tried to pry it gently but it will not come off. I'm afraid to force it. Is this the way to remove the cartridge. Can you also supply a part number for the replacement cartridge?