Done this on an X250, but the X230 should be pretty similar.
You will probably have more difficulty taking the door panel (and any waterproofing behind it) off. Chances are some of the clips will break due to age, and finding replacements can be a bind. If you have an arm rest then this is usually screwed onto the door, door opening mechanism will need to be removed also which can be a pain to access the little clip that holds the wire 'puller' on..
Taking the winder mechanism off is pretty straightforward.
Firstly wind the window down about half way so you can get to the catch that clips the mechanism onto the glass (green bit in your picture). Unclip this and then move the window back to fully closed and wedge it so it does not suddenly drop.
Mechanism is held in with three 10MM bolts. Undo these and then you will have to find which is the best way to get the old unit out.
Fitting the motorized unit should then be the reverse.
Not certain but think the winder you have does not have the safe stop module, This might be fitted elsewhere but not sure with an X230. If no safe stop module is fitted then you just have to be careful not to leave the motor energised as it will burn out the motor at worst, or pop the fuse at best.
You might or might not have wiring in the door for electric windows. If not then I can recommend this Ebay item:
https://www.ebay.co.uk/itm/181165386162?hash=item2a2e4c69b2:g:FNIAAOxygPtSwHdE Which I have fitted to an X250. All you will need is a 12 Volt supply and earth, and a suitable switch (on-off-on) to operate the window. Caviat as above, stop pressing the button when the window is fully up or down !.