I did a Black Rock kit, but I chucked a whole lotta extra White Chelsea in there, (About 3kg I think). Came out OK, but took ages to finish, about 6 weeks. Then I split it up, bottled some and secondaried the rest with raspberries, sultanas, spices and vanilla (5 different batches). Came out best with the sultanas, but it's all pretty young still, I figure I'll give it a bit of time. I'm thinking of doing another kit sometime. However, I did wash the yeast from it and used that recently on some plain ol Fresh Up green apple juice. Looks to be going well, yet to taste it. I'm thinking I'll rack it to a growler and leave it a few weeks to clear. Not sure if I'll carbonate it or just have it still.
Edit: I didn't actuall answer the main part of the question, yes, it is the same as the extract kits. Just empty the can, add the water and sugar, stir like hell and pitch. And at the end taste the syrup that's left on the inside of the can, yummy as!