to make changes to a piece of clothing so that it will fit you better
alter
to change completely
transform
to make something become larger in size and fill more space
expand
to reduce someone to a lower rank
demote /dɪˈməʊt/
to make a bigger copy of a photograph or document
enlarge
to change something slightly in order to make it better, more accurate
adjust
to change from one thing to another, or to make something do this
switch
to make something smaller or less in size, amount, or price
reduce
to become worse
deteriorate
to give or return something that you have and get something different
exchange