I found getting them in and out to be a little tricky on mine as well. Remember that the "sweet spot" for both extraction and insertion is at some point mid way between the on and off positions. After that it's a matter of some practice and feel. A LOT apparently since even having done it a good half dozen to ten times it's still a bit of a struggle for me. But it's getting easier.
Also my detent plunger has a bit of a ridge around it so I have to reach under the safety and push it in with something to let the safety snap down more easily. Next time out I'm going to round it over a little more so I don't need to do that as it becomes a rather kludgey two handed operation.
And don't forget that you also need to find the sweet spot for holding your tongue in one corner or other of your mouth or pinched lightly between your teeth while you're doing this or it's all for naught....