Super easy. Only hassle was thinking one pack would do it, and having to wait a couple days for Amazon to deliver the second... Took less than an hour and I wasn't rushing.
I'm the current "equipment manager" for my local outdoors club. The club owns a bunch of backpacking gear that it loans out to members. Think "REI Rentals" but cheaper. I've had to replace the shock-cord in several BA Copper Spurs owned by the club. I used shock cord I purchased from Dutchware Gear. It was like 1/2 the cost of the Coghlans stuff.