This thread will detail some simple mods you can do to your Vulcan that don't require a full Splitlip-esque overhaul.
Velcro Ammo Box
I got sick of the slightest little bump removing my ammo box in the middle of a fight, do I did something about it:

The picture explains it all. The velcro allows the box to still be removable, but it won't just fall off on you, either.
Pressure Switch Removal

I believed Splitlip mentioned this in his thread. The annoying little switch that used to be here keeps the gun from firing unless the orange belt-holder piece is securely closed. There's no reason to get rid of it, but no reason to keep it either. Simply cut out the switch, strip the ends of the wires, twist the ends together, and wrap them in e-tape.
Belt Holder Modification
The way the Vulcan's designed (unless I honestly missed something), if you only fire 5 rounds or so, you have to fire the rest of the entire belt before you can reload it. The Orange belt-holder doesn't open if their's a belt in it. Imagine this with a 50-round belt. Needless to say, this is a pain in the ass.

You probably can't tell in this picture, but I basically sanded down the top edge of that square hole. This allows the belt holder to still lock in place securely enough to allow the belt to feed, but also lets you open it in mid chain if you need to reload.
Air Restrictor Removal

Splitlip covered this. Just do yourself a favor and actually open your gun to get the restrictor. It's really not that hard. I don't think it's worth destroying your gun just because you were too lazy to open it.
Naturally, I took the pegs out of the belts, too. An easy way to do this is to take a pair of needle nose pliers, grab onto the peg from the back of the belt, and twist. 9 times out of 10 this will remove the peg relatively cleanly. Other times it leaves a small piece or two, but they are easily taken care of.
Barrel Assembly Removal - With a twist!
I think this is the most original mod out of all of these. Which is why I saved it for last.
What this mod does is make the barrel of the vulcan removable. And reattachable. Without opening your gun.
Removal of the Vulcan's barrel helps range and accuracy, but it also makes the gun ugly and prevents you from using the rails. I found a way to have both.
Here's how you do it. First, you need to remove it the hard way, by opening up your gun. Once you get the gun open, though, it practically falls right out. There is only one screw to remove after you get the gun open.
Now open your vulcan barrel assembly:

And cut here. It will make alot more sense if you try to do it.
Repeat the same on the other half of the shell. This is what you've removed:

You can throw that away.
It should now look like this:

You might want to sand down the bottom edge a little. It will help it fit together later.
Now get some good velcro, and put it here:

and here:

You will need something such as the small pieces of pvc I used to put the velcro on, so it can stick to the velcro on the Vulcan's main body. I used epoxy to keep the pvc bits in place.
Now you see that hook-like protrusion on the top of the assembly? You can probably tell what to do from here.

Stick it in like this, and apply some moderate upward force to pop it into place. Then you just push it down and into the socket, where the velcro will engage.
Now the front of your Vulcan is removable!
This mod is for people who can't decide whether they want the front removed or not. The only thing you still need to know, however, is that you will need something much stronger than velcro if you want to use the shoulder strap, such as one of the cabinet latches Splitlip has been using. This setup can take as much downward weight as it could stock, but upward force pops it out of place (which is how you remove it) So basically, you could stick a Unity system on this if you wanted, but the shoulder strap is a no-no unless you use a stronger attachment method.
So there you go. Here's a list of simple modifications for people who are afraid of breaking their expensive new gun. Hope these help someone.
I am definitely not through with the Vulcan. I still have plans for this.