Want to update Linsys Firmware, but modem in the way....

HI!

I put in my IP address, and get to the modem. I believe there is a way to take my modem out of the mix and update the firmware on my Linksys router, but I'll be darned if I can figure it out. I called Linksys, but they want me to sign up for 90 day tech support, and I need to spend the $$ on a new router if the firmware update doesn't solve my problems! :-/

Can anyone help me?

I have a Motorola SB6141 modem and a Linksys EA6500 router.

Thank you!!