Hiscox cases seem to be velvet over foam internally.
Not sure if the velvet will separate from the foam easily, if at all. I'd look out for one with a different internal colour you like, buy it and sell yours. If you don't want to lose the branding on it, then just suck it up as I think you may regret pulling your case to bits.
I've modded non-moulded cases before quite easily where they have external screws and when I've wanted to raise or lower the neck brace position.