With the muzzle in a safe direction,
firmly grasp the slide with your non-dominant hand: as if you are going to rack the slide. Do this with the thumb pointed back at your body, as it will be an extremely difficult an angle to attack the gun with your thumb pointed towards the muzzle.
Now, using your strong/dominant hand,
open-palm strike the tang of the weapon. Aim for the web of your hand to contact the tang (with the XD/XDm, proper technique should have you simultaneously contacting the grip safety and deactivating it, thereby allowing the slide to cycle its full stroke). As you make contact, close your hand around the grip so that you can retain ("catch") the weapon, as it should be hit hard enough to propel it out of your non-dominant hand.
This forceful blow should "shock" the slide free.
This is a method that is taught specifically as stoppage remediation on reciprocating-slide semi-auto handguns.
Should you launch the weapon downrange, do *NOT* attempt to catch it. Simply let it drop, and retrieve it afterwards.
Other ways to remediate this stoppage:
Hope this helps!