You can only change ONE letter, AND/OR rearrange the letters currently available. The first word is:
WINS
best
ebbs
bobs
lobs
boys
buoy
bout
tour
runt
rent
tent
trey
tree
reed
sere
seep
peas
upas
paua (it's a mollusc with a decorative shell) (and I can see a word that can be made from it)
Aula (german for assembly hall)
laud
deal
dole
oleo