first
open paint
step 1 open your picture
step 2 draf a few lines with your pincel or do some stripes not on the part that you wana save
step 3 go to the right south corner of the picture
and drag the sqoure to the size you want it to be
step 4 rotating
rotate it 180
now you can drag the sqoure also on the other side
final rotate it 180 agen this time so its in the good posision
than save at and go to the post an picture on the forum