Recover Office Wi-Fi Password -- 2

I have misplaced the wireless passphrase for my own office network. The setup uses a Brand B router and I currently have no administrative access, so I cannot simply log in through the web console.

Because it is my network—confirmed as an office environment rather than public or third-party—I need a network security professional who can guide me remotely (or supply a clear, step-by-step procedure) to regain control. Acceptable approaches include safely extracting or resetting the WPA/WPA2 key, flashing or factory-resetting the router without erasing critical ISP settings, and then helping me configure a new, strong password and basic security best practices.

Your work is finished when:
• I can reconnect all office devices using the recovered or newly set passphrase.
• Router settings remain intact (SSID, ISP credentials, DHCP scope) unless explicitly backed up and restored.
• I receive a concise, one-page memo summarising what was done and any follow-up precautions.

Experience with Brand B firmware, Wi-Fi diagnostics, and remote support tools (e.g., TeamViewer, AnyDesk, SSH) is a plus. Let me know your suggested method and estimated turnaround time; I’m ready to begin right away.