The swap is a pain in the knuckles but not particularly difficult if you have a long 5mm ball head allen key and access to someone with small hands to re-attach the cable.
They are painted satin black. The swap doesn't take a lot of mechanical knowledge, but it is a really awkward job that involves reaching into some tight spaces. I have swapped handles before and it was not something i was looking forward to do again. It is part of the reason why these sat around until we ended up getting the Aesthetic Creations covers. Here's Glen's old DIY:
