I've got the details at home (I'm not there) & I think they go something like;
In the sound menu, set BASS to MAX, & TREBLE to MIN
Then press the 'Channel Down' -\/- button on the TV's front panel, and the 'Index' button on the remote at the same time. This brings up the service menu.
To navigate the service menu, use the couloured buttons on the remote - the 2 on the left go forwards & backwards through the options, & the 2 on the right change the values.
When happy with the change, press the 'STR' button on the remote to store it. You have to do this for each option you change, i.e. change H-Pos & press STR, then V-Pos & press STR etc.
I'm pretty sure thats how to access the menu, but I know it took me a couple of times to press the button on the TV & remote at the same time (I know, it sounds simple
) . If that doesn't get you in, update this post & I'll check it later when I'm at home, & post the accurate instructions.
I know every post about service menus says this, & I know it sounds really condescending, but I'd write the settings down before changing anything if I were you.
Have fun.......