>>315213858
standard blender proceedure for reposing an avatar, including changing proportions:

1. in pose mode scale the bone along the local axis as required. you may need to scale the child bones in the opposite direction to keep it looking right
2. in the modifiers for the mesh, apply the armature modifier
3. in pose mode "apply pose as rest pose"
4. re-add the armature modifier to the mesh(but don't apply it)