First of all: hello. Newb here. Please be gentle with me. (but not too gentle ) So I got hypnotized by the Stipula Etruria Rainbow Prisma. i clicked "BUY" before I knew what I was in for. Fortunately it's a lovely pen so far and I do like it quite a bit, but what would make me love it is a Stub nib. Does anyone have any experience changing nibs in an Etruria Rainbow? Anything I should know? I am hesitant to do anything without some idea of what I'm doing. Any tips or advice?