If you do go for the Lubix over the Traxxas 50k (seriously, it's the same thing and you get 60CC for cheaper than the 2CC...) then even just the 2CC one will last you a long, long time. That's assuming you just keep lubing the one cube. Every new cube you keep lubed will increase the rate you use it up, of course. That said, if you do it properly you should not have to re-lube a ZhanChi with Lubix for thousands of solves.
If you're going to be replacing the stickers, take them off first. If you're not replacing the stickers that came on the cube, just leave them on and don't worry about them. Lubix won't ruin them at all if you get some on them.
Get a screw driver and take the cube apart completely. Turn a layer 45 degrees and grab an edge, twist it and pull, and it should pop out. Just mess with it until the pieces are all off. Pop off the center caps and take all the screws out. Take note of how the spring and washer is on the screw. You want the spring to go over the screw first, then the washer when you put it back together.
If you took the stickers off when you started, just throw all the pieces you not have into a bowl or something filled with water and move them around a bit. Let them dry or use something to dry them. Don't do this if you have stickers on the pieces and you want to keep them, obviously.
Optional but worth it:
Take a corner piece and an edge piece and put them together as they would be in the cube. Slide the corner piece through the edge piece as if a face were rotating, and notice if the base of the corner piece is bumping on any little "lips" of the edge piece. If there are little ridges on the edges that cause that little bump, then take a moderatly sharp edges (not like a turker carving knife or something, in fact one side of some basic scissors will do) and run the blade over that little ridge until it's smooth. Do this 48 times, that is four times per edge piece, and you will have done the 48-point edge mod. It's way simpler and easier than it may seem.
Take a middle piece (not the cap) and look inside of it. Put a little (very little) bit of Lubix on the bottom that you see in there. Basically the place where the washer will rest when you put it back together. Now look for the little ridge part way up the inside of the center piece. That's where the screw head will rest when the center piece is pulled outward. Put a little Lubix on that too. Now put a little dab of Lubix underneath the screw head where the spring will be resting on it. This will stop that annoying springy sound when you rotate some cubes.
Just put the screw into the center piece and screw it into the core, leaving about a 2mm gap when the center piece is pulled outward. Do that for the other five center pieces. Once you have them all on with the 2mm gap, pull each center piece out and put a dab of Lubix in each gap.
Now hold two centers on opposite sides of the cube, one in each hand, and flick the thing to rotate it rapidly. You should feel it getting faster and smoother. This makes it so you don't need to do a bunch of working in after the cube is assembled. Do that for each axis. I put the center caps back on the axis that I have already done so I don't lose track.
Now reassemble the cube. It migh tbe trickey if it's your first time assembling a Dayan cube, especially one with torpedos, but it's not that bad. I recommend puting in two edges, then the corner piece that goes between them. Then one more edge on that face, and the corner piece that goes in there, and so on until you have one face done. Then put the middle layer edges in. From there it's pretty simple.
Once you have it back together, play with it a bit and see if it even really needs to have any Lubix between the edges and corners. The 48-point edge mod and lubing the internals tends to be enough for a ZhanChi. If you want it even faster, put a little (really, a LITTLE or it'll be gummy) Lubix between one edge and one corner and then work it in. You'd be surprised how fast and well just a tiny bit of that stuff works.
Unlike Jig-A-Loo or CRC, that should last you for thousands of solves. I did this to a ZhanChi for myself and one for a friend in early August and he barely uses it and I do minimum 100 solves a day and our cubes still feel the same now. If anything mine feels a bit smoother just from being broken used more.
The last step clearly is new stickers if you're still using the Dayan ones. You can search the forum for information on stickers, but a Cubesmith half-bright set with bright or light blue is my recommendation. I recommend light blue for black cubes, bright blue for white. Also since I hate yellow on white cubes I'll say that I love having a black/white axis instead of white/yellow. Stickers are all preference though.
