Your choice, but you really should listen to what he's telling you, as it will be much easier. FYI the blank keys are used for other keymaps, so they might be blank on yours, but for keyboards used in other countries they'd have characters printed on them.
In any case, given your limited technical skill I'd suggest you might be better off paying the $27 (19 EUR?) for a brand new UK-layout keyboard from AmigaKit. That sounds like a heck of a deal to me, and there's videos on YouTube showing how to swap it out.
I just need to gently prise off a blank key without breaking anything. It would be good if someone told me the best way to do this.
Of course, the blank keys may be used for other keymaps, but I'm not sure which ones at the moment. I don't actually need to use those keys for word processing or anything else at the moment, because I have other computers which can produce any characters I need in other European languages I speak, meaning German, French, Dutch, Danish, Swedish, Italian, and the artifical but mainly Indo European language Esperanto. The laptop I'm typing this on doesn't even have a key between # and ENTER, while the key to the left of the Z is marked \ and | . I may soon buy a copy of the German language political party game "1990" from Vesalia, so I think I should check what the German A1200 keymap is before deciding which key to remove. At the end of the day, I do need the C key, which is also C on most keymaps, but may not need either of the blank keys.
Of course, if I fail, then I can still buy the brand new UK Amiga A1200 keyboard from Amigakit for less than £19, but at the moment I'm learning about repairs, and you've got more money than me anyway. I already know how to unplug and plug in an Amiga keyboard, because I did this when I fitted my CF hard, as well as years ago when fitting a Kickstart ROM switcher board. I'm trying to avoid spending any money I can if there's something I can do about it, such as making or repairing something myself.