Are all speaker relays removable? One receiver with two relays?


Hi there, I mean if all speaker relay COVERS are removable. I have a Yamaha AX-730 and suspect it needs some cleaning. I tried to use two nails as levers to lift the black plastic cover but it seems it can’t be removed. Not sure if I should apply more force, being afraid I may have in fact loosened the solder. Do some speaker relays have fixed covers so they have to be desoldered for cleaning? Or by cutting a hole on the cover for cleaning?

I also find a black box of the same size and shape above the relay (please see the photo) but without any identification on it. What is that?
jp2020
Relays are only removable if socketed. 

I've had older Yamaha pro amps with relays and no sockets, so I added them. :)
Thanks, Erik, judging by the photo I posted, do you think the black plastic cover of the relay can be pulled off? If so, I am thinking to clean the relay with a strip of thick paper with electrical cleaner without removing the relay itself.
Do some speaker relays have fixed covers so they have to be desoldered for cleaning?
Do not try to clean the contacts, just replace it with a Fujitsu FTR-F1AA024V
https://www.mouser.ca/ProductDetail/Fujitsu/FTR-F1AA024V?qs=llYdsnK8Kc2ETH%252B7Ws971Q%3D%3D
I also find a black box of the same size and shape above the relay (please see the photo) but without any identification on it. What is that?
It is a similar relay, could be replaced by someone, maybe the data is printed on the side wall instead on top.

I've removed the covers to relays like that before. They aren't really intended to be removed, so its likely they will not snap back in place very well once you've cleaned the relay contacts.

IME cleaning relay contacts is problematic. When the contacts have got to the point that they are able to corrode, the relay is on borrowed time and you will find that the contacts will need service again, sooner rather than later. If you can find a replacement you are better off replacing the relay itself. IOW only clean the contacts when you have no other choice.