Is it possible to reduce the base mesh if it already has a skin and animations?

Hello Everyone! Is there any way to reduce the character if it already has a skin? The usual reduction does not help. In unreal, the same giant throws. Animation has already been done, I would like to do “less blood”, well, if there is still such a possibility. The basic mix and animations are made in the Maya program. Thanks for your attention!

I don’t know for Maya, but my character rig in Blender I can slap on a Decimate modifier and that works just fine. Re-importing the rig into unreal mostly works fine but I get a dialogue pop-up to “reset fbx materials”. So some materials were crushed off the decimate modifier anyways. All the animations work just fine.