Probably easiest if you know the basic rules and then look at the SQL manual for syntax.
Basic rules are:
- the columns in the Primary Index cannot be changed if the table has any data in it. You need to create a new table with different PI columns and then INSERT/SELECT from old table to new
- when adding or dropping partitions you basically have to add at the 'ends' of any existing range. So if your current range is 1 Jan 2010 to 31 Dec 2017, you can add new partitions for (say) 2009 or 2018 or you can drop partitions at the start of 2010 or the end of 2017. you cannot simply drop partitions for (say) 2015.
There are a couple of variations to that but those are the basic rules.
For SQL syntax and further details can I suggest that you look in "SQL Data Definition Language Syntax and Examples" and "SQL Data Definition Language Detailed Topics" under the ALTER TABLE command.