Tiler,
Do a meter at a time at the most, you can practise it of course! Get a couple of small tubs, different brands preferably and get going on some made up pretend floors in your garage at home with some 100 x 100 tiles (to get more grout practise in).
You have to use an epoxy grout float, which is a harder rubber float that you spread a small amount of epoxy on to and then press into the joint. The trick is to try and not get too much on the tile surface.
Then once you have spread a meters worth, get your epoxy emulsifying scouring pad thing and do small circular motions with it when the pad is slightly wet.
Then use a sponge to wipe the final grime off the tile surface.
It's important to not let the epoxy dry on the tile, you can't get it off the next day like normal grouts. You have to do everything with your 1 square meter while the epoxy is wet, get it looking really clean, grout joints well filled, tiles all shiny and smooth again and no sticky texture to them, then do another meter.
Hope this helps