You'll need some bland salad oil. Don't waste your money on expensive olive oil for this because you would not even be able to taste the olive character and olive oil is prone to denature during the processing.
And you'll also need a funnel and a fine mesh metal sieve. A cloth or paper filter will plug up. Don't go there.
Remove any leaf material and long pieces of stem. No need to fuss over the stem bases and green caps. Leave them on. Wash and drain.
Fill up a blender or food processor about half way with the peppers, and toss in a few teaspoons of salt.
Pour in vegetable oil (canola works well) to a few inches over the peppers, or under if they float. Cover and power up. If your blender or processor tends to leak, better wear rubber gloves. Leave it on high for maybe 15 seconds. Whatever it takes to make it look like a neutron smoothy. If things jamb up, add some more oil to thin the emulsion. DO NOT ADD WATER, however.
Put a tall sauce pan in your sink, and dump the atomic smoothy into it. The smell will be pleasant, not spicey at this point.
Put the pan on the stove, with lid on tightly, and turn the burner on high. During this part of the process Homeland Security Department rules, which we strongly recommend you abide by, require that you PROMISE NOT TO LEAVE THE KITCHEN, that you NOT GET INVOLVED IN A CONVERSATION, and THAT YOU NOT START READING TREEHUGGER.
After a bit of rumbling and sizzling, water vapors will start coming out from under the edge of the lid. As soon as such violent bubbling and steaming gets underway turn the burner off, leaving the cover on and waiting to lift it only when no more water vapor is coming out. The cooking only takes 4 or at most 7 minutes. You don't want to drive off all the water because if you do you'll be driving off those lovely flavors and making the kitchen atmosphere unbearable. The goal is simply to break the emulsion.
Turn on the kitchen fan and peek inside. The pepper flesh will have coagulated into semi-sunken blobs. If the emulsion is still finely divided you haven't quite cooked it enough to separate the oil from the water and fruit bits. Put it back (tightly covered) for just a minute or two more cooking if that is the case.
When done cooking, pour the mixture through a fine screen sieve set upon a pan or bowl. Make sure the receiving vessel will be convenient for pouring the finished product into the funnel you'll use to bottle the hot pepper oil.
Plan on dumping out the filtrate from the sieve periodically.
When cleaning up take care not to touch with bare hands any spilled oil. This stuff is really hot.
If you plan on making several batches or will use a very large pan, it would be a good idea to do the cooking outdoors. A camping stove will work fine.