Hi Ding, Thank you for your question. To remove the RP51304 handle from the faucet you will need to loosen the set screw found on the bottom of the handle if you are facing the faucet. Once loosened the handle should pull off. You can then remove the trim sleeve and the bonnet nut to access the cartridge. Here is a link to the parts diagram of the model T14438 trim that uses this handle.http://www.deltafaucet.com/customer...