There is an step by step explaination in the readme which yaou should read carefully!
You can run the SQL statements(!) even when 0.7 is still installed as you like. I recommend to deinstall 0.7 and reinstall 0.9 with the installer (nevertheless you have to apply the following statements):
and additionally when you upgrade 0.7b and below to 0.9b:
ALTER TABLE `jos_uddeim` ADD `crypthash` VARCHAR( 32 ) DEFAULT NULL ;
and additionally you upgrade 0.8b and below to 0.9b:
ALTER TABLE `jos_uddeim` ADD INDEX `datum` ( `datum` );
ALTER TABLE `jos_uddeim` ADD INDEX `totrashdate` ( `totrashdate` );
ALTER TABLE `jos_uddeim` ADD INDEX `totrashdateoutbox` ( `totrashdateoutbox` );
ALTER TABLE `jos_uddeim` ADD INDEX `toread_totrash_datum` ( `toread`, `totrash`, `datum` );
ALTER TABLE `jos_uddeim` ADD INDEX `totrash_totrashdate` ( `totrash`, `totrashdate` );
uddeIM & uddePF Development
CB Language Workgroup
CB 3rd Party Developer