Not using the pristine-tar branch

[Tong Sun <suntong001@users.sourceforge.net>]

Hi,

I saw many people are stop using the "pristine-tar" branch, since the
"pristine-tar" tool can do just that.

If I want to do the same,

- what should I do, if I have a repo that contains such pristine-tar branch?
- If I have a repo that contains such pristine-tar branch that has
never been pushed, would removing the pristine-tar branch recover the
space wasted before, so when pushed to the server, it'd look like the
branch was never before?

Detailed steps appreciated. thx