One of the common gripes about quick release spring bars is that you cannot easily replace the spring bars if they become faulty, because of the knob that gets in the way. That is actually not true! Quick release spring bars can be removed and inserted into your watch straps without the use of any specialised tools.
Below are two videos showing you how quick release spring bars are inserted and removed into watch straps, through the notch for the quick release knob. Leather that are not as pliable might face some difficulties, and you might need to stretch the leather a little, and it is perfectly normal.