delete from big table............

 Hi,

I've to delete from a big table where I've 260 million rows,

I've to delete some portion of data , I know deletion is not a good option.

I planned 

1. take export of the table

2. create table dup_tab as select * from org_tab where   xxx=-------.

3. drop table org_tab .

4. rename table dup_tab as org_tab.

is there any other method better than this with less downtime ?

is there any step I'm missing in this method ? 

any help will be appreciated.

thanks 

tcy