There is a tutorial in SW on a snap type latch. I'd recommend you review that.
I definitely suggest to use prescribed displacement for such problems and then extract the reaction forces.
I know nothing about your geometry but you should be aware that the three things that static FEA hates to hear is snap, click or pop so use small time steps, add fillets if needed etc..:)
What's more, base on my experience the final reaction plot should give you a smooth curve with no sudden spikes during insertion/extraction. The only exception is the final "click" stage where you might in fact expect some spikes depends on your geometry.
Here's an example of a good looking Insertion/Extraction force graph (Automotive fasteners, POM):