Changing the combination on a Diplomat safe

[QuietCanuck]

I recently acquired a "Diplomat File Safe model SD-200" and want to change it's combination. I have the current combination for it, but I would simply like to change the numbers. before I start removing the back of the door to access the combination wheels, I first wanted to check and make sure I will not cause some unexpected problem by doing so without following a specific procedure (such as it tripping a tamper mechanism etc). Therefore I was hoping someone on this forum might have heard of this brand and model of safe, and have some information on it.
I have searched the web and only found that it was made in Korea, and although the Diplomat safe company seems to have a website, it was not working well in my browser and they did not respond to an information request.
The safe has a Sargent & Greenleaf dial (but no model info on the dial), and uses a key as well.

So my questions are:
1) Can I safely remove the back of the door and start examining the workings of the mechanism without following a specific procedure?
2) Does anyone have any general info on the safe (fire rating, type of insulation, security rating, etc)?
3) Does anyone know of a website that I can dig around on that may have more information on Diplomat safes?

Thanks in advance, and any information will be much appreciated.

[deception]

I'm assuming you have the safe open, the model number of the S&G should be on the back of it.

You stated you already know the combination, there should be a line to the left of the opening index, at the 10/11 o'clock of the dial, simply dial your current combo in there, and insert your change key, dial in your new combo to that same change index, once finished, take the change key out. Test and make sure your new combo works alteast twice before you close the safe. That's it.

As far as removing the the back plate of the lock, if you do that you'll set off the internal relocker, not really a big deal, unless you close the safe with the back plate off, and then you'll need some help.

[QuietCanuck]

Thank you for the information.

There was no model number at all (no sticker, plaque, or stamping) on the inside of the door that I could see when I had it open, which is why I was thinking of removing the inside of the door which appears to be held on by 8 small screws.

While I did not see a change key slot on the inside of the door, there was an approximately 1" dia plastic plug in approximately the middle of the inside of the door, so possibly that covers the change key slot. If it is likely to not cause a problem prying the plastic plug out, then I will try that next week once I can open the safe again (I can not open the safe currently as the heavy beast is lying on it's back waiting to be moved to another room).

[QuietCanuck]

Here is an update for those who read this in the future and wonder what the outcome was:

The safe has now been moved to it's final location, placed upright, and the door opened. The plastic plug indeed did cover a "change key" slot.
I had some problem opening the safe because one of the combination numbers was not exactly as I was first told (it was 2 digits off so I opened it with a bit of blind luck). I decided to be cautious and make sure the lock was actually OK and had not shifted it's combination due to wear etc, so I disassembled the door and everything inside it (inc the S&G lock). The door's relocker was not sophisticated (no glass, just steel) so it posed no problems for disassembly/reassembly of the door like I thought it might. The insides of the S&G combination lock were in great shape, so I simply cleaned, relubricated, and reassembled it with the factory specified grease and new spline key. I then bought a change key and changed the combination without any problem. It has been working perfectly for 2 months now (very smooth and consistent), so I am very happy.

If anyone else is considering disassembling their safe door and lock, my new advice is as follows:
If you can not afford to have the safe permanently lock on you, then call a professional just to be safe. Otherwise, if you want to learn something about safes and are a careful person, take it apart cautiously and you will learn a lot (I know I did). Block the door from closing when working on it, and before you disassemble anything, take lots of photos of the area as a reference before you disassemble it. If you take apart the the S&G lock, clean all parts carefully in alcohol, buy the S&G specified grease and follow the S&G guidelines for where to apply grease and the amount to be used. Be very meticulous, and test, test, test, before you close the safe door (should be obvious, but worth stating).

Thanks everyone for your help.