Network beginner question about a switch setup

[SquarePeg]

Basically brand new to networking. Trying to setup a new Linksys SLM2024 smart switch we just bought. The manual says to use 192.168.1.254 to access the config pages but when we do the dsl modem/router config pages appear instead. How do I get around this and setup my network correctly? For now we have....

dsl modem/router=>
switch=>
=>computer 1
=>computer 2
=>computer 3
=>computer 4
=>computer 5
=>computer 6

Also, all computers are Mac.

In the end we will add a server in the mix but I'm not sure exactly how we want that setup just yet.