[Q] What is the safest way to gain S-off on HTC DHD? topic

Friends

I have a HTC Desire HD, with the following specs:
CyanogenMod 11-20140804-unofficial/M9-ace
Android 4.4.4
It has TWRP as recovery
SHIP S-ON RL
HBOOT-2-00-0029
RADIO-026.14.04.28_M

I want to install a new port from Mustaavalkoista, but before that I want to make my phone s-off.
But I am struggling doing that, so wanted to ask for some ideas how I can best proceed. I do not want my phone bricked.

Thanks for good suggestions,
Calle