1. ctrl-o open source text file 2. ctrl-h open replace dialog * set "replace unit" to "Chars" * set "replace scope" to "Line" * set "Unit Number Filter" to 2<2> * set "Search for Pattern" to:
3. click "Replace", done! Note: * 2<2> means number start from 2 and increasing by step of 2. * [^\n] means non-return character.