Mine was quite challenging to remove. There are four nut/hex-head screws. The front of the cabinet cover comes off easily with four screws. Then the front two screws into the IOTA area easy. For the back two, I had to get a 1/4" socket with extension fed in there and could just barely feel the tip of the screw head with my finger to place the socket, then slowly back the screw out 1/4 turn at a time.
I eventually figured out that the reason mine was not working was that it was never wired in from the factory. Oops! Wires sitting new/untouched/unstripped behind the unit. Very happy with the Victron unit I replaced it with, though.