the way SupportiveEntity suggested is the by far quickest and easiest way to do it.
I’m not gonna say it isn’t possible without blender, it is.but it’s most certainly not easier.
You would for starters need a different physics asset for each limb (A physics asset tweaked to behave like the mesh has only that limb, ignoring all other limbs), then to separate the limb you would spawn another identical mesh and apply a custom material to it that uses an opacity mask to hide all of the mesh except the desired limb, and for the original mesh you would probably just use hide bone by name to make it disappear.
From there you’d have to make adjustments, like for example the spawned mesh will need to be in the exact same pose as the original mesh, which means you have to save the pose of the original mesh and load it for the new one when it is spawned so that the limb starts at the correct location.