Okay, I recently installed a new to me set of Simplex Retro-Friction shifters and after disassembling and they work really well. The issue is I was not able to remove the spring which has quite a lot of grime on it. I've soaked the lever in solvent and the spring looks clean, but I'm wondering if with normal use it should be easily removed and it is now gunked up where the solvent can't reach. so:

1) Is the spring removable without a Herculean effort?
2) Should the spring and retainer be greased?

Thanks