Unlike many other models, the Nokia 6280 doesn't seem to made so that users can remove the display cover themselves. This annoys those who get dust in between the actual LCD and the display cover, which is a lot of owners... Actually, over time, it's everyone.
Inspired by a short instruction on the Mobileburn.com forum, I thought a more precise instruction would be useful.
Thanks to Moby
Step 1: Locating the clips holding the cover in place
First we need to release the two upper side clips and the top clip.
Open the slider, place the phone so the rear side is facing up and note where the top clip and the upper side clips are located.
Step 2: Loosing the upper clips
If the second upper side clip is released, the opposite clip tends to pop back in place . Therefore release one upper side clip, then the top clip and then the other upper side clip. A upper side clip is released by pulling the backside (currently facing upwards) of the display cover outwards with a finger nail or similar.
Step 3: Loosing the lower side clips
To release the lower side clips run a fingernail, a slim piece of plastic or a credit card from the upper side clip, along the gap between the display cover and the slide, until the lower side clip is released. Repeat for the other side, but don't try to loosen the bottom yet, as you will risk breaking the two bottom clips.
Step 4: Removing the cover
Now all clips are released, except the two bottom clips, which aren't visible yet.
Close the slide carefully, but stop if the slide is much harder to move. In that case the cover is loosening grip at the bottom clips and needs to be pulled back up for now.
When the slide is closed it can be removed entirely by sliding, not tilting, the cover furthermore downwards.
Step 5: Remove dust
Now you can remove dust from inside the cover. If you as most users, don't have an air spray, you may blow air yourself, but be careful not to let any spit go along. Sucking your mouth dry beforehand is actually worthwhile - weird to describe, yet relevant.