Cut the fat and skin in pieces.
Render the fat in a pot over a medium-low flame.
When the fat is rendered and the pieces with a lot of skin start to float to the top, skim off the pieces with a spider and set them aside. If some of the skin is still has fat attached (some will) don't worry about it.
The process will probably take a long time, but just stick with it until all the skin's been removed and there's nothing but fat in the pan When no more pieces float to the top, allow the rendered lard to cool, then strain it so that it's completely clean without any brown bits. You can use either a fine sieve or a colander lined with a couple layers of cheesecloth. The colander will do a better job, but if all you're going to do with the lard is make cracklings it's not that important.
Return (some or all of) the lard to the kettle, and heat to frying temp -- 350 - 375F is good.
Drop a few pieces of skin into the lard (don't overcrowd). In about 30 seconds, the skin will fluff up and expand to about three times it's size. Use a spider to remove the skin onto a towel lined dish, season immediately. Continue frying in small batches until it's entirely done.
The oven method is good for getting crisp skin on a pork belly, and would be my first choice for that cut. But it's not nearly as good for what you have. You can make it work if you want, by cutting the skin and fat into lardons, seasoning them, putting them them on a sheet, placing in a hot (as hot as your oven will go), preheated oven for about 20 minutes, then reducing the oven to around 375 and just letting them cook until the skin turns GBD, probably another 30 - 60 minutes -- with the time depending on a lot of things. This method will leave a fair amount of fat with the skin; and -- as already said -- is better for pork belly.