Resize a mob at 1.12.2 - MCreator 2022.2

Hello everyone. I'm working on a mod with some creatures which are supposed to be big, but the model is too little. I tried to resize it in Blockbench, but the texture doesn't fit anymore even after resizing it in same proportion. Making another take too much time and, around forums, I saw something about GL Manager (import org.lwjgl.opengl.GL11;). I couldn't apply it correctly and maybe there is something I'm doing wrong.

This is the code I applied:
@SideOnly(Side.CLIENT)
@Override
public void preInit(FMLPreInitializationEvent event) {
RenderingRegistry.registerEntityRenderingHandler(EntityCustom.class, renderManager -> {
return new RenderLiving(renderManager, new Modelcarnifex(), 4.5f) {
protected ResourceLocation getEntityTexture(Entity entity) {
return new ResourceLocation("warhammer_fourtyk:textures/carnifex.png");
}
protected void preRenderCallback(EntityLivingBase entityIn, float partialTickTime) {
GlStateManager.scale(2f, 2f, 2f);
}
};
});
}