Since you mentioned that your W161 device is bricked do you see the LED light on the front of the router, what color the light is?

have you done with basic trouble shooting like power cycling modem and router?

There is no option to download the firmware for the router that will be pushed automatically while setting the router on the surfboard central app.

I’ve done hard reset. Reinstall the app and after connecting through app there is error appears 0003-2501.

Please make sure that the satellite should be powered off while trying to setup the main router.

http://arris.force.com/consumers/articles/General_FAQs/mAX-W61-Wi-Fi-Cable-Modem-Internet-Setup

Also, I request to send us the screenshot of the error code.

Finally I managed to install the main router and satellite. But when I turn off optimization the app is crashed and won't open. Even reinstalling the app did not help. It's started once and now doesn't

I suggest resetting the main router and start over the app setup process again.

http://arris.force.com/consumers/articles/General_FAQs/mAX-W61-Cable-Modem-Internet-Setup

On the network optimization step, I suggest waiting on the same screen until completed.