How to access and reset my Netvanata 1550-24p? Unknown IP - unknown password etc.

[HainTech89]

I have this 1550 I got used and I can't figure out how to access it and reset it and/or upgrade the firmware etc. 

I'm a little more familiar with other brand switches so I know basic concepts but not sure how to get done what I need. 

I've been previously directed towards the below article here but it doesn't seem like it's for my switch. 
https://supportcommunity.adtran.com/t5/General/Restoring-an-AOS-Device-to-Factory-Default/ta-p/32557

What can I do? I'm lost. TIA

[BradR]

HainTech89, you can bypass the passwords, so that you can reset/change them,  if you have physical access to the box with console cable by entering the bootstrap mode. The following link should help you out.

https://supportcommunity.adtran.com/t5/General/Password-Recovery-in-AOS/ta-p/30419