So, you have a tar file with absolute what?

Don't do it again. :-)
After you have already created one, the easiest way to "un-absolute it" is to use GNU tar. This is the default behavior when creating or extracting files with GNU tar.

You can find GNU tar at

You are welcome.

Another tip came in from Gregory L. White who suggested using pax:
# tar tvf export_home.tar
tar: blocksize = 3
drwxr-x--- 201/1        0 Sep  5 10:16 2003 /export/home/gwhite/x/

# pax -r -s ',^/,,' -f export_home.tar

# ls
export  export_home.tar