How to make model height lower ?

Hi i would like to change the value of an animated model.
I would like its Z being -60 instead of 0.
How can i do that please ?
I guess i need to edit bones, not only vertices positions but don't understand how to do it.

Oinkerwinkle's Geoset Translator (the name is misleading; it does affect bones... sometimes) might do it for you.

Otherwise, you need to use Magos' to put everything underneath a new root bone, and give that root bone a single keyframe at zero that moves it to -60. Then give it an arbitrary global sequence, so that frame is applied all the time. Might do strange things to your extents, so hope that Geoset Translator works, really.

Thanks, sounds understandable for me :)
I will try that.