Simple question-W126, Fuel pump relay-where?

[unkl300d]

My 1989 300SE needs to have some fuel related parts replaced.

These include the Fuel pump relay, switch over relay and fuel pump/filter.

The latter is a no brainer.
The relays' position, I am not too sure of.
Behind the firewall and in line with the air filter (ie behind that general area) are two black relay boxes.
One is for KLIMA and the other is part number 002 545 92 05.

I suspect the latter to be the fuel pump relay.
Please correct me.
Where is the swirch over relay?
Also, to remove the relays, does one just pull up and remove or is there a bracket to loosen????

Thanks

Denis