Is there a simple way to resize/ scale a head piece with physics?

[Xanins]

Trying to adjust the lionmane_0.nif and lionmane_1.nif mesh to be 10% smaller (90% the size of the original mesh) so that it will fit this race: https://www.nexusmods.com/skyrimspecialedition/mods/73738

Lion mane mod: https://www.nexusmods.com/skyrimspecialedition/mods/72166?tab=description

I've been trying using nifskope and outfit studio, i did manage to get the mesh to the correct size in studio, but it broke the physics and it became static. :[

If anyone can help me resize the meshes while keeping physics intact, that would be amazing.

[scorrp10]

Try this:  go back to the original meshes.   Open lionmane_1.nif in NifScope,  expand the root, click the NPC Head [Head] node and change its Scale to 0.9.  Save.  Do the same with lionmane_0.nif.    See how that goes.