Hi Marianne, I searched for "HH65" in the user manual of the dtx450, and found the procedure how to set it up on your drum kit, at page 45. Direct link to the user manual: https://ca.yamaha.com/files/download/other_assets/4/713374/dtx400k430k450k_en_om_d0.pdf (found using google)

I hope that this will help!