How to recover Zyxel Keenetic 4g II password without reset?

Question

ZyXEL

Hello!
There is an office remotely, there the Internet is distributed through keenetic 4g II, telephony and pptp weigh.
The password from the web muzzle was lost, because there is no way to physically get there and reset it, I want to start brute forcing (http authentication), can anyone do this? I will not "drop" his number of requests by chance?
And does it have protection against such attacks?

Answer 1

Artem : yes, I meant password guessing) but how can I pull out the hash of the password?