Rip in my Driver's seat

So the top of the driver's seat in my truck is shredded, there's a hole about a foot long and 6 inches wide in it. There's also some fray on the bottom where it will eventually start tearing as well...I just noticed the bottom part. I called the Dealership and they want $144 just for the upholstery for the top part of the seat. I haven't called about the bottom yet. How hard are these to replace once I have the new upholstery? Thanks guys!