I am NOT a mechanic just a DIY'er that's been doing this a long time. This is how "I" make access to the fuse board. If in doubt, seek a professional automotive specialists help.
A request form a view Maynard Chitty for a video on how to get at the main fuse board on a smart 453 (Right Hand Drive). its a very straight forward process but us right hookers, have it nowhere near as good as the left hand drive folks. Their fuse box is in the glove box and very easy to access.
Always take photos of what you are doing is my best tip. That way you always have a reference point for when you have to rebuild something. On this occasion, you need to follow the process very carefully was there isn't much wiggle room on the one side.
It's straight forward enough but, access is still limited. The board is VERY deep in the car. I would invest in a long Fuse removal tool to make life a little easier (you could use extra long pointy pliers but I never like the idea of poking around hard to reach places with metal ion my hand, especially if we are talking electrics.
Link to the Amazon tool
www.amazon.co.uk/Kissherely-P...