Spawn a USD scene, get the RigidObject from this object

Omniverse Isaac Sim
1

In IsaacLab

I have a USD defining a scene with Xforms which reference Rigidbodies

cfg = sim_utils.UsdFileCfg(
        usd_path="/workspace/isaaclab/shared/ramp1/usda/0001.usda"
asm_prim:Usd.Prim = cfg.func("/World/Origin1/Asm0001", cfg)

I want to load in a given scene and get the Xforms.
/scene/xform1@rigidbody/geometry
…

Would someone be able to point me to an example where a scene is spawned from FileCfg and the a prim is accessed as a RigidObject. If I traverse the scene I get Usd.Prims.

How do I access the RigidObject api for sim purposes from a Usd.Prim, such as adding a force or stepping the simulator

Edit for reference: I want to access part0 as RigidObject for example
0001.usda

#usda 1.0
(
    defaultPrim = "assembly"
    upAxis = "Z"
)

def Xform "assembly"
{
    float xformOp:rotateX = -90
    double3 xformOp:translate = (0, -0.019999999552965164, 0)
    uniform token[] xformOpOrder = ["xformOp:rotateX", "xformOp:translate"]

    def Xform "part0" (
        prepend references = @../busd/b0.usda@</b0>
    )
    {
        quatf xformOp:orient = (1, 0, 0, 0)
        double3 xformOp:translate = (0, 0, 0)
        uniform token[] xformOpOrder = ["xformOp:translate", "xformOp:orient"]
    }
... etc

referencing rigid bodies such as:

#usda 1.0
(
    defaultPrim = "b0"
)

def Xform "b0" (
    prepend apiSchemas = ["PhysicsMassAPI", "PhysicsRigidBodyAPI", "PhysxRigidBodyAPI"]
)
{
    float physics:mass = 0.08879914
    bool physics:rigidBodyEnabled = 1

    def Xform "geometry" (
        instanceable = true
        prepend references = @./b0_instance.usda@</b0/geometry>
    )
    {
        double3 xformOp:translate = (0, 0, 0)
        uniform token[] xformOpOrder = ["xformOp:translate"]
    }
}