I have 3 spacers in my headset and I'd like to remove 1. If I do, the stearing tube will stick up higher than the stem; there wont be a proper gap for the stem cap to compress the headset properly. I assume I have to have the stearing tube cut/faced. ? Is this something I can reasonably do at home?

Also, how do the manufacturers decide on how many spacers (how much space) to put in the headset?

Thanks!