Hey Anton, I'm not too sure about the tb, but as far as the distributor is concerned I can understand your trepidation as I went through it as well....First there is only one way it can go back in, so there's no real fear of pulling it, just take the cap off, leaving your plug wires connected, and set it to the side, then the adjustment bolt for the dizzy needs to be taken out then the dizzy should just come out, if you notice at the end of the shaft of the dizzy there is an offset slot, only goes back one way like I said previously, common things to check for on the dizzy are shaft play (rotate the shaft, if it's hanging up anywhere or is very audible you might have problems) the plastic vacuum advance plates over time tend to heat up and crack and won't advance the timing anymore...usually you can check by using a vacuum gage on it and visually checking that the plate moves, or just getting some clean vacuum hose and sucking on it, needless to say, if it doesn't advance you could rebuild it, or take the easier route, I got a rebuilt from a parts store for like $140 with the core, (nissan dealer quoted me for a new one at $400!)
good luck, and have fun