Apparently you have to break the safety lever and stretch the frame with pliers to remove the locking insert and trigger.

http://youtu.be/SEfsHwHb3bs

I'm going to go our on a limb and ask "why do you feel those last 2 parts need to come out ?"

If it were mine , I would break iit down to that point , clean & lune with a little CLP and be done with it

One of my friends with armorer certs that regularly detail strips his pistols to do trigger jobs on them said after seeing that video he'd never buy an FNX-45 because stretching the frame is a "no no" and if the trigger bar spring were to break it requires being sent to the factory to be done properly, and in a SHTF scenario that can't be done, and for a SIG all he'd have to do is pull off a grip panel and replace the spring, and he doesn't buy guns he can't service himself.

His words, not mine. I told him guns aren't meant to be detail stripped often and in a SHTF scenario that bad you'd have to improvise as you would be with a bunch of other things anyway.

That was my argument, that there was flex built into the polymer frame to withstand recoil impulses and the slight prying it took to get the locking block out wasn't going to warp or damage the frame.

He said "plastic isn't supposed to flex." Needless to say, that's not true in the context of polymers used by the firearms industry.

Alright, I spoke to John over at FNH USA tech support. He says there is in fact a proprietary method of removing the unlock block that doesn't involve prying the frame, they don't sell the tool to do so or disclose what that method is, and they don't offer armorer classes.

So, final verdict: Not a design flaw intended for prying the frame, but a proprietary method and tool is used to remove the locking block, all of which is undisclosed at this time.

The pliers are an end user improvisation. The question now is, in the future, does one carefully proceed with the pliers method, or take a really careful look at the part assembly and try to figure out how the proprietary method/tool works, and maybe try to reverse engineer it?

 

Probably because most other other modern polymer pistols can be detail stripped with a paperclip.

Of course, you break the paperclip.  So maybe FN has them there.