Hrm? A simple x has always worked for me

In any vi I've encountered the past 20 years, 'x' deletes the character under the cursor. So, if your cursor is on code, you first need to move the cursor to the indent. Hence '0x' to move the cursor to the first column, and delete that character, or '^X', which moves the cursor to the first non-white space character on the line, and then deletes the character before it.

Abigail