On my 20" 590 I can see the threads on the end of the tube giong into the receiver, so I dont think its pressed in.
Brownells sells pliars specificly for this, but with a little bit of weatherstripping or duct tape around the jaws of some channelocks (to keep from scratching the finish) you could have pretty much the same thing for a lower price.
The curved jaws of some visegrips would probably work out better, but care must be taken to keep fron chrushing the tube.