I need help taking my p-90 apart I pull the slide back and pull the slide stop out but at the end it stops and wont come out is there a trick to this any help would be great
(If I understand this correctly) The slide stop doesn't come out.
To Field Strip the Ruger P90
Rack the slide back and latch it.
Remove the magazine.
Reach through the ejection port and push the ejector forward as far as it will go. It will stay there.
Ease the slide forward.
Push the slide stop through from the right. (The slide needs to be in a "just right" position, a fraction of an inch from fully forward to be able to do this.) The slide stop will stick out about an inch, but in the P90 it will stay with the gun.
Once the slide stop clears the "little round thingee" on the bottom of the barrell, you should be able to pull the slide with barrel, spring and guide rod, forward and off the gun.
Reassembly is the reverse of the above. Don't forget to lever the ejector back to it's normal position, and note the orientation of the recoil spring.
You normally would not take it apart any further than this.