Please modify this letter to make it more polite. He modified his views on same-gender marriage.
source: WordNet 3.0
add a modifier to a constituent
source: WordNet 3.0
cause to change; make different; cause a transformation
The advent of the automobile may have altered the growth pattern of the city. The discussion has changed my thinking about the issue.
source: WordNet 3.0
To change somewhat the form or qualities of; to alter somewhat; as, to modify a contrivance adapted to some mechanical purpose; to modify the terms of a contract.