OK, let's start from the beginning.

Drop magazine, clear chamber, lock slide to the rear.

Use any implement to lower the sear release lever. I find a pen or small screwdriver a heck of a lot easier than pulling the widget in the butt.. Make sure the sear release lever is all the way down-don't force it. BTW, if your pistol has a magazine disconnector, the sear release lever is the one on the left when looking from the rear of the pistol.

Rotate the takedown lever to the 6 o clock position and hold it there. Pull the slide back slightly to allow the slide stop to release and then allow the slide to go forward. It should slide right off the frame. If it doesn't, the usual issue is not having the sear lowered enough to clear the striker leg.

The disassembly process really isn't faulty. May not be as slick as the Browning High Power, but much better than some others.

If all else fails, lock the slide back and remove the striker assembly from the rear of the slide. That'll let you get the thing apart and figure out what you're doing wrong.