Surgery
Surgery, the best way to look at people's insides. It is very useful for augmenting other players, or yourself. Or creating monstrosities.
How to do it.
Make sure the patient is lying down, either on a surgical bed or the floor.
With a surgical tool in hand, such as a scalpel, alt-click on the patient.
A menu listing body parts will open up, each labeled something like "Pick HumanHead". There will also be an "Attach procedure."
Clicking on one of the body parts will open another menu giving you the option of removing that bodypart, or for some bodyparts, opening it up.
Clicking on a procedure will start that procedure.
After starting the procedure, you need to use a specific sequence of surgical tools on the patient (make sure to be on help intent).
You can just try to use all your tools on the patient until one works.