Hi Mabry
Before attempting to remove the keys mentioned, try to determine the side of the key that is rubbing the most. Do this by using your index finger and thumb to grip the front if the key. Depress the key whilst moving to one side. Does it rub considerably? Depress the same key again, this time moving towards the opposite side. Does it move more freely this side? In this way you can determine which parts of the key are rubbing against a. The front key guide, b. the hammer butt. Once you have made a note of which side of the key(s) are rubbing, removed them taking note where they came from!
To remove the keys, use a flat screwdriver the same width as the pink anchor at the rear. Set the keybed up so that it faces you (playing position - fronts facing you). Insert the screwdriver into the slot and once in, press the pink in the slot towards you. As you do, pull the bottom of the back of the key upwards (you many need to wiggle the screwdriver slightly as you do so) and the key should come free.
Having removed the key (and noting where they were taken from, you will need to adjust the key so that it no longer rubs. WARNING: This is a delicate operation and less is definitely more when it comes to this adjustment so take it slow, bit by bit.
You may notice at the rear of some of the keys, little grove marks. What are they? Well, these are the very marks made when Fatar did their initial regulating of the keys. If a key rubbed, they would use something like piano wire cutters to 'move' the key over so that it no longer rubbed. Usually a rubbing key will not look straight from the front, rather if will probably be wonky (even if only slightly).
Let me know when you've got to this point and I'll attempt to instruct further Mabry,
Kindest Regards,
Chris