And it was a real pain in the butt to get the water tube back in. But don't worry, it can be done... When I called the local appliance shop to ask advice, the technician actually laughed at me and said he tries to avoid letting the water tube come out at all costs.
Before starting anything, unplug the fridge or shut off the circuit for it. If you have energy running to the fridge when you open up the front panel, you can very (very) easily blow some of the delicate circuits in the two different boards that are in there. I found out the hard way that they cost about $100 to replace (each).
First, try and pull as much of the water tube from the door as possible to give you something to work with. Use just your hand (not a pliers or anything) and give it slow but pretty steady pressure. You can actually pull it rather hard. You might only get 1/4 to 1/2 an inch or so, but every little bit helps.
Second, make sure that there isn't any calcium buildup in the hole that the water tube goes into.
Third, make sure the tube isn't bent out of shape - this will keep it from going in. I flipped my front panel over and pushed the tube in the hole from the other direction to make sure.
Fourth, gently curve the water tube so that the end points straight down. This will help when you are putting it back in.
Fifth start putting everything back in, including reconnecting the power cable to the front panel. Some models have a little hole the right or left of the water tube that you can stick your finger in to help push the water tube down. Just keep working at it. You only need to get the tube about 1/8 of an inch into the hole for it to fit snugly. Ideally you can get the water tube to go all the way through the faucet so it is visible at the other end. FYI - when assembling these things, they actually have about six extra inches of tube to work with, and then they snip off the excess. I kind of wish they would have left a little extra for us to use.
I hope that helps. It took several tries (over two days because I kept getting frustrated) for me to get it. But once I did it was good. Avoid using any type of glue of caulk to keep the tube in place. Remember this is your drinking water.