In the following overview you'll find a set of loops that can be done to adjust the trim of a paraglider.
Also known as Cow Hitch, Larks Hitch or Anchor Knot; for details see also Wikipedia.
The length change for the Pile hitch is very similar to the Girth Hitch Plus. It is for most wings easier to fit it over the maillon or soft link though. For details on this loop, see also Wikipedia.
To see how it's done, also compared to the Pile Hitch see https://knots.neocities.org/pilehitch.