Unpicker here too. It is important, however, to place a pin across the end of the bar tack so that you don't go too far when you make the cut.
I don't know what equipment you have so far, but I consider the basics to be good, sharp cutting shears and smaller scissors, a tape measure, pins, said
unpicker (seam ripper), markers (either pens or chalk), good quality hand sewing needles,
and a seam guage. Other equipment is, of course, an iron and ironing board. I have been sewing for nearly 30 years and this is pretty much my basic kit.