I did this right before my baby was born, (I wouldn't have time to do something like this with a newborn) and I am finally getting around to posting it. We bought this slider and foot stool for cheap from a neighbor who wanted to get rid of it. I was going to leave it the dark green color because I thought it would be too much work, but I got really tired of the color. I took off the cushions and found it would be really easy to redo. I don't have a full tutorial, but I do have some steps to show you.
let me borrow used his staple gun to staple the fabric to the foot stool cushion. And made the corners look really nice.