need to get the done soon but I never took apart a monitor How hard is it to separate the monitor from the tube?
You are going to need to separate the deflection board (aka monitor board) and neck board (the little board with that is connected to the neck of the tube )from the tube. To do this, you are going to need to UNPLUG THE MACHINE. I would even wait a couple of days, just to be safe after unplugging the machine, although a tube can hold a charge for a long time.
No offense, but it sounds like you are totally green in this area, so proceed at your own risk here. This process, if not done right, can pose risk of serious electrical shock! It's no joke.
Also, remove all jewelry and metal from your body.
I'm not familiar with the innards of a 4-slot Neo. You may need to take out the monitor completely to do the following. I just swapped out the monitor on my Neo Goldie, and it came out without much hassle. However, it was only a 19". Your 25" monitor is really heavy, though, so you will want a second person to help you out, if you need to physically remove it.
In order to remove the neck board and the deflection board, you are going to need to discharge the monitor. To do this, you are going to need a grounded flat head (slotted) screwdriver. You can achieve this by attaching an alligator clip to the metal shaft of any normal slotted screwdriver. Connect the other end of the alligator clip to the metal framework of the monitor. This will ensure the ground.
On the tube itself, you will see a large suction cup. Making sure that your screwdriver is grounded, you will need to slide it under the suction cup. Under the cup, there are two metal prongs called anodes, which go inside of the tube via the anode hole. These prongs need to be popped out of the little hole that they go into. You will probably have to play around with it for a while before you get them out. They need to be pushed inward towards the center of the suction cup, and then pulled upward. Take your time. During this process, you may see an electrical spark. That is normal and OK. It is in fact what you are TRYING to do. This is the discharge.
Once the cup is off, I would wait another couple of minutes, and touch the now exposed anode hole with the STILL GROUNDED screwdriver. You may see another spark. At this point, everything should be safe.
Now, to remove the neck board (the little one with the color pots), gently slide it off of the color gun. (The exposed plastic portion will look like the barrel of a gun.) It can stay attached to the main deflection board.
From here on out, it should be pretty much obvious what to do in order to get the deflection board/neck board removed from the rest of the wiring. Take photos, so that you will know later on what went where. The only thing that may be an issue is the black dag wire from the tube, going to the deflection board. It may in fact pop off via a jumper, or you may have to straight-up cut it. If you have to cut it, don't worry: You can always strip it and re-solder it.
I hope that this helps. Remember, be very careful when you are discharging the monitor.