I held the head and the gun under the tap....hot water did the trick; it snapped right in.

3,5 months later, I did this again with the General Weiss AT-ST. Worked like a charm.

My tip:

Place the cannon on a table near the edge

Press the canopy gun "housing" down on the gun and it'll pop right on

Thanks, that worked great!

My tip:

Place the cannon on a table near the edge

Press the canopy gun "housing" down on the gun and it'll pop right on

That's what I did after a little shaving of the nubs.

I'm not being facetious, make certain you're not inserting the gun upside-down. I tested this, and it's very difficult to put the chin cannon in upside-down, but not impossible. My model's cannon slid in quite easily when inserted with the correct orientation.

I've been too lazy to fix it, plus I don't want to break it trying to get it out. It's Weiss so its easy to rationalize that it is upside down for some experimental new reason.

I just shaved off the plastic till it fit. No biggie.

Am I the only one having had success with (very) warm water?

Or was I simply the only one trying it?

I used it last night, worked great.

I used a file and a sharp hobby knife. Bit of work but it fits great now.

Assembled both AT-ST and General Weiss this way.

I carefully used the hairdryer on the area where the cannon snaps into.

Ya I had trouble too, ended up using thumb muscles and popped it in like a man.