Notices

Can u please write a little tutorial "how to change a lockscreen picture and other settings for noobs"? I would like to be able to change it but I don't know how...

I added new application to easy ui configuration. It's testing version but now you can easy change wallpaper, quickbar shortcuts and position of elements. Wallpaper must have 480x800 dimensions. For now you must manually restart lockscreen to update changes:
sudo stop qmllockscreen
sudo start qmllockscreen

I can't download a normal version. Some google stuff related (google shortner, to be exact). How to download?

It's fixed now.

Recently I flashed my phone and now I'm using stock Maemo with stock kernel. Just installed QMLLockScreen (have also installed dependencies), restarted my phone and it's not working. I only get black screen on the settings and when trying to unlock device with qmllockscreen.
What to do?
Can I give u some x-term output? How to do that?

Try in terminal:
sudo stop qmllockscreen
/opt/qmllockscreen/qmllockscreen
then in new terminal window:
/opt/qmllockscreen/qmllockscreen-settings

It's still blank screen.
First x-term window outputed this: Nokia-N900:~# /opt/qmllockscreen/qmllockscreen
file://opt/qmllockscreen/qml/vertical-v2/main.qml:2:1: module "QtQuick" is not installed
import QtQuick 1.1
^
44040194
root is not in the sudoers file. This incident will be reported.
desktop is: "1a00005"
get_profile "general"
get_modem_state "online"
i2c battery value: 85
getMafwStatus(): 0
^C
Nokia-N900:~#

Don't use sudo when you are root.
I guess installing qtquickcompat should solve problem.

Installed it, rebooted the device. Qmllockscreen is working but it's a mess (cannot screenshot it and don't have a camera at the moment. It's showing my background picture and icons, music player shortcuts are moved to the left upper corner and so are battery percentage and signal strength and they are overlapping) and settings are still not working, only showing blank screen.

You don't have to restart it all the time. Just use (not as a root):
sudo stop qmllockscreen
sudo start qmllockscreen

Try once again running it in terminal.