Opening Viewsonic PT775 monitor

[NewLimey]

Hi:

I have an old and trusty Viewsonic PT775 monitor which I have had shipped to me here in the UK. I packed it quite carefully, surrounding it with feather pillows and bubble wrap but when it arrived and I unpacked it, 2 of the 5 control buttons on the front panel were slightly pushed in and misaligned, making it impossible to adjust video settings. It is the button marked with number 1 and the down arrow button.
Can someone please let me know how to open the monitor so I can have a look to see if it might be a fairly simple mechanical adjustment or repair?
I've removed the swivel base and screws which hold the front panel to the main body of the monitor, but am not sure how to separate them, and don't wish to force it and possibly cause damage.
If this appears NOT to be something I can easily fix, can you recommend where I might find a servicer in the vicinity of High Wycombe, Buckinghamshire, UK? (I'm originally from Toronto and purchased it there.)

Any help would be appreciated.
Michael