I've managed to figure out how to get that tail ramp out, just requires a bit of extra muscle

Step 5 of base mode however says I have to pull up that base thing out of his chest (so it becomes a raised platform) to attach the large purple cannon. I can't get this piece out. As with all my new g1's though, i never try to force transformations out to avoid breaking anything. Do I just need to muscle it out as well?

Here's the scan - step 5 on the far left.

http://www.botchthecrab.com/archive/..._trypticon.jpg