To do it right I would loosen the emergency brake cable from under the van
and adjust the brakes using a screwdriver to turn the star adjusters that
are accessed throught a small hole the brake backing plate (first have to
remove the small plastic/rubber plug).  When the rear brakes are properly
adjusted, then you tighten up the emergency brake cable from under the van.

However, if your brakes seem to be working fine you may just have to
tighten up your emergency brake cable.

Pascal
'84 Westy