Kinda depends on what kind of rope you are splicing. If it's regular (sold core) climbing rope, then I would not attempt that, since it's quite complex and having testing equipment would be advised. When I bought my rappel rope (Canyon Elite) I had the supplier put in a spliced/sewn loop, but they test their loops, and supply primarily to the arborist trade, so I was comfortable with that.
If you are splicing hollow braid (eg. amsteel, dynalite, etc), then that is pretty easy to learn to do and to create strong/safe splices and loops. All you need is some fids, some knowledge/practice with how to do brummel locks and the like.