Shame about the tray. I've not known one to be that tight that it needs knocking out but it certainly won't help. Sometimes they can be a bit tight if the barrel has been fitted wrongly, ideally the magazine is put in place and the barrel slid into the block so it goes into the slot on the magazine just touching the recessed area, then you tighten the barrel retaining screws, it should be a easy to slide the magazine out with only a slight resistance.
To strip, remove the small hex screw in the middle of the clear perspex cover, hold the cover in place at the same time, lift the cover slowly and put a finger on the rotor then you can control the spring pushing it up. You'll feel the tension on the spring so just let it unwind itself as you steady the rotor.
You don't want to cut the spring, this will affect the tension negatively. When you reassemble the magazine, use the lightest tension you can, here's a couple of images I took a while ago when playing with the Royale magazine, here's what's inside:

Here's how it goes together:

I put a pen through the rotor with the spring in place with no tension to show where the rotor stop is in relation to the magazine body detent, just turn anti-clockwise and push down so A engages behind B, hold in position, pop the perspex cover back pop the hex screw back in and nip it up. If the front cover is too tight or loose, there's an even smaller hex screw in the back of the magazine to control how far the front screw can go in - well thought out design!!