P97DC problem, it won't take down

[Oldtimer]

My daughter's fiancée brought me his uncle's P97, which his uncle had taken down and put back together.  Now it will neither accept a magazine nor take down.  The magazines go in to just below the lowest witness hole.  I have tried to hold the ejector down with a pipe cleaner, but even with the ejector held down, the slide will not come off.  Any ideas would be appreciated.  I hate to have a .45 and not be able to burn off a few rounds.  Thanks in advance.

[j104wd]

should be some lines on the slide and the frame you need to line up then you can push the slide release through the frame and let the slide go all the way forward. The slide stop also needs to be pushed down into the mag well before the slide will come off.