You do not want your holster soft and supple. The stiffness of the holster is what you need for proper retention.
Your holster will loosen up. Put your gun in it and let it sit for a few days. You can also wear it around the house for a few days too and that will help speed up the process.
Do not put any type of leather conditioner on your holster. While it might make it softer, it breaks down the fibers in the leather. This is not something you want.
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