Order your glass and maybe mirror and arrange a way to get it home safely. I bought the table and cut first, creating a period of time where I had a substantial hole in my daily use table.
The glass had to be custom cut for the Ikea table's dimensions. Tell them you want it for a table so they can do some edge work and they use the right glass.
It would also be good to have it professionally tinted, especially if you have never done tinting yourself. Any mistake you make, you will know where they are, and you'll be able to spot it. It takes awhile to cure and it's a tough job to do cleanly on this big of a sheet of glass. I did my own as a novice, it turned out ok, but there are flaws, and they make me wish I had it tinted right
Get your mirror as well, dimensions will vary or have something custom as well. If I find my receipt, I'll update with my dimensions.
Acquire the table. These things are mostly made of cardboard. Not joking. For that reason, when you start cutting apart large internal sections of it, it start to become VERY weak. Try to leave a large edge section to help with the structure of the table, the glass adds allot of weight.
I marked off a section that I wanted to cut and used a large dremel cutting wheel to cut out the top of the table. I wish I had the jigsaw then.
Inside you will find a honeycomb structure of cardboard, cut this out to be the same size as your top cut out. Your table is very fragile now. Be careful.
Painting. I used the cheapest home depot flat black paint I could find, I painted the whole top, inside, covered all my dremel marks. ;) I also laid out the led strip and put a sticky dot over each emitter, I then used some Duplicolor engine enamel and spray painted the whole strip.
I found a few wood planks to fit on the inside of the table which helps with the structure and also gives the led strip a place to affix to, these were painted as well.