Eat more spinach
I know what you mean. I have a 430. It's the shortness of the cocking arm that makes for more pressure when cocking it. My 48 is a doddle in comparrison with its long sidelever. Even my AR8 Blaser N-TEC takes more effort to cock in its Compact Pro config than the standard long barrel version. You'll just have to man up to the task.
I suppose a thinner wire spring, allowing for a couple of extra coils, so it doesn't become coil bound might help. Couldn't tell which one though, as I use mine as it came putting out 11.2fpe.