Twice now I've rebatched soap. It's not an easy process. I had quite a bit of cold-processed soap I'd made, with lemon scent, from which the scent had entirely gone. I had many bars left, and it wasn't selling at all. So rather than have it sit around I thought I'd try rebatching. Rebatching is basically melting the soap down again, fixing whatever you did wrong in it the first time, and forming it into bars again. Here's an example of my failed lemon soap:
When you zip your soap closed, try to get out as much air as possible. Then place that bag in another ziploc -- a gallon size one. Zip it closed, also eliminating air from the bag. Then immerse the doubled bags in a large pot of water that you've brought to a boil, and then turned down to a good simmer.
Then I removed it from the hot water again, snipped off one corner of the bag (a good-sized hole b/c this stuff is THICK), and "piped" it through the hole, into my juice can mold. One quart-sized bag of grated soap filled up this juice can. Even when piping it out, it is not a liquid. It's very thick and difficult to manage because the ziploc bag is extremely hot. It's difficult to mash it into the mold and very difficult to get all the soap out of the bag.