Most people here remove the footrest and then drill it. It is only plastic, there are 3 screws around the footrest so just remove those.
When I did mine, it looked like someone had already had a go at the screws for some reason, and the one was threaded so could not be removed, so I just got 3 nice looking screws and pushed them through the plastic to keep them in. I would not worry about the 3 holes in the plastic though. I presume taping htem in place would not work due to keep moving your foot, unless it is strong tape.