Discuss
[edit]Unless the need for a merge is really obvious, it may be worthwhile to start a discussion before doing a merge. To do so, simply add the merge template to the bottom of the article you are intending to do away with, and explain on that article's talk page why it should be merged into the other.
Merge
[edit]Simply cut and paste the relevant content from the merge candidate to the merge target. Try to integrate the content well, so the merge target does not read awkwardly post-merge.
When merging content, attribution must be retained to comply with the Wikivoyage:CC-BY-SA licence. If merging X into Y, this can be done by leaving an edit summary of "content merged into [[Y]]" on the source article and "CC-BY-SA content merged from [[X]]" at the destination article. Yet better is to use [[Special:Permalink/xxx|X]] instead of [[X]], where xxx is the oldid= number from the permanent link you find in the toolbox in the margin of X or from the page history.
Redirect
[edit]The last step is to turn the now empty article into a redirect to the merge target. Yes, empty article; it's better to blank the old article once you've finished moving the content to save a reader who may hit return from seeing what looks like a normal article, only hidden.
Do not list the redirect for deletion; if any of the content is re-used, the edit history (or at least the list of contributors) must be retained for attribution. Under the CC-BY-SA free licence, there is no "merge and delete" as this would break attribution of edits to the original author(s).