/remini can delete either an item, or a whole [section] of an ini file
/writeini -n test.ini section1 item1 value
/writeini -n test.ini section1 item2 value
/writeini -n test.ini section2 item1 value
To remove only 1 item:
/remini test.ini section1 item1
To instead remove the entire [section] then don't specify the name of an item to remove
/remini test.ini section1