The rubber biscuits? Jack the back of trans up just a little, unbolt the center bolt from each biscuit, slide the old biscuits out and the new ones in, put the new bolt and the bottom cushion into the holes, install nuts, add the cotter pins. Make sure you buy the correct biscuits from a reputable supplier. Lots of places think those things are all the same. They are not.
Almost exactly the way he said but it is probably best to take the nuts off the bolts before you jack the engine up. Probably a 30minute to an hour project depending on how fast you move and what you forgot to take under the car with you. I'd be on he hour side now but probably would been under 30 when I was 30.