Backed up files on a time capsule

Hi,

My hard drive was reformatted whilst being repaired wiping all of my data. And then rebooted without re-installing my files from my Time Capsule. So how do I now re-instal my files from my last back up?

And when I re-install those files, will they merge with the documents / data that I've created since rebooting? Or do I have to back that data up first?

Pinkafeld