Upgrading from 1.5.2.1 to 1.5.4.1 MAJOR ISSUE

Hi,

Tried to updgrade 1.5.2.1 to 1.5.4.1 following the documentaion here on the opencart documentation page.

Everything worked great uploading the files as the guide,
I try going to:
http://Bilkamera.se/install

I see the updgrade page buth when I do that i receive following error:

Could not Execute: ALTER TABLE `oc_bilkamera_se_affiliate` MODIFY `status` tinyint(1) NOT NULL DEFAULT 0 COMMENT '';
ALTER command denied to user 'xxxx' for table 'xxxxxxx'



And now when i try to accesss my admin page I receive following:

Notice: Error: Unknown column 'salt' in 'where clause'
Error No: 1054
SELECT * FROM oc_bilkamera_se_user WHERE username = 'xxx' AND (password = SHA1(CONCAT(salt, SHA1(CONCAT(salt, SHA1('xxxxxxxx'))))) OR password = 'xxxxxxxxxxx) AND status = '1' in /www/webvol17/c1/xxxxxxxx/bilkamera.se/public_html/system/database/mysql.php on line 49



Could someone please advise how I can fix this?

I´m shitting my pants now

Update:
I did a restore on my backup from my webserver and everything is back to normal on version 1.5.2.1
So i´m not shitting my pants anymore but I would still really need to upgrade since I need to have Klarna payment module installed, and from the looks of it - it´s only supportet in 1.5.4.1>

Any advise is helpful