Change get_calendar() display options?

Get calendar is a very powerful site navigation tool, but there is very little documentation for how to customize it’s appearance in WordPress: remove days of week (S S M T) from table, change number of columns (why not just one going down whole page sidebar), change number of rows in table (two across the top), display only numbers with items, place month listing on same row as numbers, more.

In short: I want to remove days of week (S S M T), display everything (month title and numbers for days) on one line (if it wraps div), and place previous and next button below.

Moreover, I’d like to do this without hacking “general-templates.php” file, but with functions.php or css. If it comes to it, I suppose hacking core WordPress files is an option.