i've seen a couple of answers on here, and i don't know which to do for reseting my ecu. i've seen just pull the neg cable off, i've seen pull both of them off, and i've seen pull both of them and touch them together, so which is it?

 

Don't ever touch a positive to a negative wire even if the positive isn't hooked up to a battery source there could still be power somewhere along the wire and that could reek havoc to your electricals. Normally taking the negative terminal off will do the job, 5 mins should do it, though I've heard of cases where overnight was the only thing that worked.