Kristi's method is safest. But if you're brave.
Backup Your database and use Caution with SQL Queries... untested
UPDATE w3t_Announcements
SET A_Board = 'heartcore'
WHERE A_Board = 'sex'
UPDATE w3t_Boards
SET Bo_Keyword = 'heartcore'
WHERE Bo_Keyword = 'sex'
UPDATE w3t_Last
SET L_Board = 'heartcore'
WHERE L_Board = 'sex'
UPDATE w3t_Moderators
SET Mod_Board = 'heartcore'
WHERE Mod_Board = 'sex'
UPDATE w3t_Online
SET O_Board = 'heartcore'
WHERE O_Board = 'sex'
UPDATE w3t_Posts
SET B_Board = 'heartcore'
WHERE B_Board = 'sex'
UPDATE w3t_Subscribe
SET S_Board = 'heartcore'
WHERE S_Board = 'sex'
I think that'll update everything. <img src="https://www.ubbcentral.com/boards/images/graemlins/wink.gif" alt="" />
Again, backup your data first to be sure. <img src="https://www.ubbcentral.com/boards/images/graemlins/wink.gif" alt="" />