You could try lubricating them before inserting. Simplest option is to simply apply water with a wet finger. If that doesn’t aid insertion enough, or if they’re uncomfortable in your ears, next step is a water-based lubricant like Oto-Ease, which is like a thick personal lubricant.
If still no good, you could try an oil-based lubricant like Miracell ProEar. I’ve ruined a couple of receivers by using too much ProEar in an attempt to get adequate relief. Here’s how I apply it now:
Spread some ProEar on a finger, transfer it thinly from the finger to the mold (avoiding the receiver port), insert the mold in my ear, remove it from my ear, apply more ProEar to the now-dry mold, and re-insert it in my ear. This way I get an effective coating between the mold and ear canal without having oil ooze into the receiver port while it’s in my ear. Avoid getting ProEar on the aids themselves while handling them.
Water is enough to get my right ear mold in, and it’s always been comfortable. My left ear mold was uncomfortable for quite a while before I got used to it, and I have to use ProEar on it. I had a feeling that the problem was my ear, not the mold, so I didn’t feel that having it redone would help.