Please note that the Pentax name is SDM (not hdm), it is noted on your lens.
Here on the forum, the 1st link below gives/provides you with links / instruction. There is an English speaking forum, which the second link directs you to. Both Forums contain maps (German: Karte) to show you the closed Forum member that you could contact. Please note that most Forum members do not dive so deep into the technical details for their gear to be able to execute such a modification. Also needed is an older camera.
40456504nx51499/tipps-und-tricks-f41/tutorial-sdm-auf-stange-programmieren-t27820.htmlhttps://www.pentaxforums.com/forums/10- ... video.html