You can use the Mask and Extract tools.
In a nutshell:
o Mask the part you want hollowed
o In the mask menu, set the Shell Thickness
- Positive number puts the shell inside
- Negative number puts the shell outside
o Tap Engrave/Emboss
The new shell will be a separate object.
o For the inner object, you’ll need to check the Inverse Culling option in the Materials menu.
o Turn off visibility of the inner object
o Select both parts
o Voxel merge them
You should now have a hollowed part.