dyazdani said:
You need to set the speaker on its "back" (lay it on something for protection and to keep weight off the posts). Hit the bottom of each rail with a rubber mallet and they will slide up, allowing you to pull them off.
Careful, it depends on the age of the SL3. Some SL3's require the rail to go DOWN, which means hitting it on the top. Might want to double check with the factory (based on your serial numbers) as to which direction your need to go.
Note in the pic below that the metal slides let the rail screws slide from bottom to top.
Also, once you remove the rails, the SL3 panel is only held by some Velcro, which will hold it for a bit, but eventually, the panel will fall. So leave the speaker on its back if you leave the rails off (or remove the panels).
To change the panel, first pull the panel off the Velcro being careful to watch the pigtail that goes to the terminal block on the front of the unit (see Pic). Loosen the terminal screws and remove the pigtail and the panel can now be set aside and replaced by reversing the process.
When re-installing a panel, be careful to maintain the tape protecting the double-sided foam insulation along the length of the panels.
If the sticky part of the foam is exposed, then sliding the rails back on is harder (or will rip the foam).
Oh, also, if you just ordered panels, you are likely to get the new ‘clearspar’ panels. Much nicer looking than the originals.
Enjoy!