Do you have a specific reason for doing so?? Chanmin wanted so bcuz he can transport it easier to gigs with cabs already provided, just he likes his amp's tone.
No reason why not, provided you got the tools and skills to do so. Or you got the carpenter and money to do it for you.
A combo actually signify portability, as one person can settle the movement anytime. Thus not a good reason.
So the only reason is vainity here, for us human it's not a bad reason either. I also take vain actions from time to time, like they say, to be seen.
I must say that cabinet making and tolex upholstering (covering) is a special skill by itself. So be well prepared, if you are looking at it from a hobby perspective. Even myself, I specialise in the electronics. I know the requirements of cabinet making, but I do not possess the skill to do so.
Just one consideration for you. You might not be able to convince the equipment owner to let you plug you head into their speaker cab. Like they say fear of the unknown.
Unless it was me, I can read the rating on you head to see if it's compatible with my cab. Then I will allow you. Normally if I see something funny being done to my equipment without my prior consent, I will screw the person left right, even if its ok.
Remember messing with own equipment is at own risk. No one want others to mess with their equipment either.