More in detail:
You could use keyboard shortcuts:
Ctrl+Left/Right:
. Subtitles time correction -/+
. VobSub subtitles dec/inc delay
Shift+Left/Right:
. Subtitles time correction -/+ (small steps)
. VobSub subtitles dec/inc speed
or you could indeed re-sync using e.g.
SubSync, which I personally find very easy and simple to use and it does its job perfectly.