Sed , Replace a "variable text" inside of a statement

Please Help... I am trying to manipulte the following line

Before :
<user:Account_Password>002786</user:Account_Password>

the password is the "variable", i need to delete / omit the password in the file, (it occurs several thousand times)
so the tag line looks like

After:
<user:Account_Password></user:Account_Password>

how can this be accomplished using sed commands.

I have been trying to resolve this for about 2 days, i am a novice to sed and now i am reaching out to the experts.

This should work for you.

echo "<user:Account_Password>002786</user:Account_Password>" | sed -e "s/\(<user:Account_Password>\).*\(<\/user:Account_Password>\)/\1\2/"

That rocks and its works. Is it possible to get an interpretation of the code so i am not just cut and pasting and not understanding it.

Thanks for your time in advance.

Steve

sed -e "s/\(<block>\).*\(<\/block>\)/\1new\2/"

Thanks a bunch