Seiko Bullhead

Photo from google, not actual watch.
So my dad was on vacation in Bangkok and chanced upon a good condition Bullhead and purchased it.
Condition is not too bad, time keeping is good and chrono works and resets properly.
However, i have no idea how to change the date and day besides adjusting the time (i.e. forwarding the time by 24 hours to change the date).
Is there any way to change it faster and to synchronize the date with it as well?
Apologies for the noobish questions but i've googled and nothing similar came up!
Cheers.