Make a “Change Pitch” of -12 half-steps. You can also download “Rovee”, a free voice changer VST plug-in. It’s OK for such things. I’ve used the preset “Female to Male” - although it is already a male voice.
It produces additionally a slight tremolo or vibrato effect but you can make it more pronounced at the end of sentences: Apply the tremolo effect (I’ve used 20 Hz and a wet amount of 70 %) on certain phrases.
For other words, just select them and press ctrl-r (this repeats the last effect on the new selection).