There are two ways to fix a cluwne, both are pretty easy if you have a good medical team. Neither involves death by the toolbox, sorry guys!
The Non-Thorough Way.
1. Snatch cluwne from the hands of the Greytide and gun-itchy security.
2. Fix up all the damage the cluwne has gotten already. (Because that has almost certainly happened by this point.)
3. Get them to surgery, then grab your scalpel and hit organ manipulation for the head. Do some slicing and remove the tumour in their head. NOTE: It will keep coming back. So keep cutting it out until it stops doing so!
4. Once your patient's tumour is removed, and his/hers head is stitched back up. Apply some mutadone and mannitol and viola! One fixed cluwne! NOTE: This cluwne will still be called "cluwne" and the gloves and mask will still be irremovable, sadly IPC's cannot be fixed.
5. Splash some fluorosulfuric acid on the cluwnes face. It will burn away the mask. You may have to fix some burn damage afterwards!
6. Lop off the cluwnes hands and replace them, thus getting rid of the gloves! NOTE: Thank's to @FPK for the last two items!
The Thorough Way.
1. Snatch cluwne from the hands of the Greytide and gun-itchy security.
2. Fix up all the damage the cluwne has gotten already. (Because I'm tired and copy pasting the first two points.)
3. Acquire a humanised monkey (you can make them through genetics or giving a monkey some unstable mutagen).
4. Drag your cluwne to the genetics, genetic modifier. Save his UI and print an injector. Then give it to your humanised monkey. He should look like your pre-cluwned cluwn (hopefully) with his name too!
5. Now, simply take the brain from the cluwn. Put it in the humanised monkey. Fix any brain damage or infections and viola! One non-cluwne human!
There we go! A guide to fixing cluwnes, I'm honestly waiting for the honkmother to smite me.
NOTE: Following this guide is liable to get you honk-squaded or cluwned yourself. Perform at your own risk!!!