Download tiny_mce here:
http://tinymce.moxiecode.com/

Install tiny_mce within the javascript directory of mantis
This now means that the path for tiny_mce.js is located here:
javascript\tiny_mce\Tiny_mce.js

We need to make a few changes which i cannot handle within the plugin itself

Modification of plugins\MantisCoreFormatting\MantisCoreFormatting.php
Comment out the kines :
$t_string = string_nl2br( $t_string ); (3 entries)


Modification of core\email_api.php

Add the following lines around line 990, just before "try"
// here should we allow the plugin to manipulate the body of the emails using html2text
// or should we simply send the emails as html mail such that this is not needed
// 	$mail->IsHTML( true );
event_signal( 'EVENT_MAIL_BODY', $mail ); 
// end of the modification

Modification of issues_rss.php

add the following lines around line 213, just before $rssfile->addRSSItem
// here should we allow the plugin to manipulate the body of the rss-feed using html2text
event_signal( 'EVENT_RSS_BODY1', $description ); 
event_signal( 'EVENT_RSS_BODY1', $comments ); 
// end of the modification 

Modification of css\default.css
Replace line 9:
p                { font-family: Verdana, Arial, Helvetica, sans-serif;}
with:
p                { font-family: Verdana, Arial, Helvetica, sans-serif; margin: 0; padding: 0;}

Modification of config
Add the following line:
$g_html_valid_tags = 'p, div, center, table, tr, td, li, ul, ol, br, big, small, tt, pre, i, b, u, strong, em, strike, blockquote, h1, h2, h3, h4, h5, sub, sup, a, hr';
