I just set out to clean the contacts on my turn signal cancelling unit but am unable to remove the plastic cover which shelters it. I removed the four screws which seem to hold the upper column cover ( which covers the unit), but it won't budge and I didn't want to start prying at anything. I don't see any other screws for that piece. Are there more hidden somewhere? Do I need to remove more covers from the steering cover to get at them? Thanks.