You can buy the add a fuse accessory anywhere if it doesn't come with the kit from PFYC, or ZZP. If you haven't ever done something like this, I'd suggest buying the kit, and either getting help or posting when you're ready to do it.

it looks very easy. maybe im reading it wrong but is the zzp kit for 2 seats or 1?

did the heated seats have any effect on the leather like making it crack or anything like that cuz i was wanting to do this to my car and wanted to make sure it wouldnt damage the leather.

I've had mine about 6 months longer than SSEi95, and nothing. My seats look like the day I bought the car.

Although I haven't driven my car in months (winter storage), they do work well and have not affected the seats condition. After installing them I don't know how I survived without them before.