i had to change WIFI modem and cannot access the WIFI extender EX6110

> my internet provider supplied modem [...]

   Not a very detailed description of that device.

> [...] the provider sent out a new modem which came with a new
> identification number and password. [...]

   "identification number"?

> The proble is i cannot access the EX6110 to reset to the new modem

   Why not configure the wireless SSID and passphrase of your
(unspecified) "a new modem" so that they match those of your old
(unspecified) "my internet provider supplied modem"?

   Rather than screw around with the settings on your extender, and
every other wireless device which you have, why not screw around with
(only) your one (unspecified) "a new modem"?