Changing the default login credentials to internet on my samsung phone
Mentioning your Android version would have made it easier to provide specific instructions, but then it's pretty easy

Press or tap Menu button &rarr;Settings&rarr;Wireless &amp; Networks &rarr; Wi-Fi

Long press your office Wi-Fi network &rarr; Forget

Go back to Wi-Fi settings page, your office network will show up (if it doesn't Scan for it). Enter your username and password and save. Subsequently, it will connect automatically and show your office network name instead of technician