I did not have to remove the entire Extruder Board to replace the Interface Board!
Take the 4 screws out of the right side of the tool head housing and gently pull it slightly to the right. This allows for placing the Interface Board more easily.
With the FPC Cable, it goes lower on the Interface Board than it may seem, but once inserted into the small slot where it is supposed to go, it will stay there as the bracket is screwed in.
Make sure to refer to the link in my original post to see which side to place the bracket. Hint: it is the side that will make the FPC Cable tighter than if the other side was used.