2 ways, both with their problems.
1st way. Simply move all the files from the wordpress folder to your root folder. The potential problem is this might (probably will) throw all the links out, so it won't work.
2nd way. Add a .htaccess file to your root directory. Put this:
CODE
RewriteEngine on
RewriteBase /wordpress/
RewriteRule ^(.*)/$ $1 [L]
The problem with this method is that it's really complicated, and that might not be the right thing to put. Can someone who knows mod-rewrite better than me check it?
swordz